1. The art of polite disagreement
While the inane spats of YouTube commenters may not be representative, the internet has certainly sharpened the tone of debate. The most raucous sections of the blogworld seem incapable of accepting sincerely held differences of opinion; all opponents must have "agendas".
2. Fear that you are the only person unmoved by a celebrity's death
Twitter has become a clearing-house for jokes about dead famous people. Tasteless, but an antidote to the "fans in mourning" mawkishness that otherwise predominates.
3. Listening to an album all the way through
The single is one of the unlikely beneficiaries of the internet a development which can be looked at in two ways. There's no longer any need to endure eight tracks of filler for a couple of decent tunes, but will "album albums" like Radiohead's Amnesiac get the widespread hearing they deserve?
4. Sarah Palin
Her train wreck interviews with NBC's Katie Couric were watched and re-watched millions of times on the internet, cementing the Republican vice-presidential candidate's reputation as a politician out of her depth. Palin's uncomfortable relationship with the web continues; she has threatened to sue bloggers who republish rumours about the state of her marriage.
Before mobile phones, people actually had to keep their appointments and turn up to the pub on time. Texting friends to warn them of your tardiness five minutes before you are due to meet has become one of throwaway rudenesses of the connected age.
All sports fans of a certain age can tell you their favourite Ceefax pages (p341 for Test match scores, p312 for football transfer gossip), but the service's clunking graphics and four-paragraph articles have dated badly. ITV announced earlier this year that it was planning to pull Teletext, its version.
7. Adolescent nerves at first porn purchase
The ubiquity of free, hard-core pornography on the web has put an end to one of the most dreaded rights of passage for teenage boys buying dirty magazines. Why tremble in the WHSmiths queue when you can download mountains of filth for free in your bedroom? The trend also threatens the future of "porn in the woods" the grotty pages of Razzle and Penthouse that scatter the fringes of provincial towns and villages.
8. Telephone directories
You can find Fly Fishing by J R Hartley on Amazon.
9. The myth of cat intelligence
The proudest household pets are now the illiterate butts of caption-based jokes.
Scrabbling around in your pocket to dig out a mobile phone may not be as elegant as glancing at a watch, but it saves splashing out on two gadgets.
11. Music stores
In a world where people don't want to pay anything for music, charging them £16.99 for 12 songs in a flimsy plastic case is no business model.
12. Letter writing/pen pals
Email is quicker, cheaper and more convenient; receiving a handwritten letter from a friend has become a rare, even nostalgic, pleasure. As a result, formal valedictions like "Yours faithfully" are being replaced by "Best" and "Thanks".
When almost any fact, no matter how obscure, can be dug up within seconds through Google and Wikipedia, there is less value attached to the "mere" storage and retrieval of knowledge. What becomes important is how you use it the internet age rewards creativity.
14. Dead time
When was the last time you spent an hour mulling the world out a window, or rereading a favourite book? The internet's draw on our attention is relentless and increasingly difficult to resist.
15. Photo albums and slide shows
Facebook, Flickr and printing sites like Snapfish are how we share our photos. Earlier this year Kodak announced that it was discontinuing its Kodachrome slide film because of lack of demand.
16. Hoaxes and conspiracy theories
The internet is often dismissed as awash with cranks, but it has proved far more potent at debunking conspiracy theories than perpetuating them. The excellent Snopes.com continues to deliver the final, sober, word on urban legends.
17. Watching television together
On-demand television, from the iPlayer in Britain to Hulu in the US, allows relatives and colleagues to watch the same programmes at different times, undermining what had been one of the medium's most attractive cultural appeals the shared experience. Appointment-to-view television, if it exists at all, seems confined to sport and live reality shows.
18. Authoritative reference works
We still crave reliable information, but generally aren't willing to pay for it.
19. The Innovations catalogue
Preposterous as its household gadgets may have been, the Innovations catalogue was always a diverting read. The magazine ceased printing in 2003, and its web presence is depressingly bland.
20. Order forms in the back pages of books
Amazon's "Customers who bought this item also bought..." service seems the closest web equivalent.
21. Delayed knowledge of sporting results
When was the last time you bought a newspaper to find out who won the match, rather than for comment and analysis? There's no need to fall silent for James Alexander Gordon on the way home from the game when everyone in the car has an iPhone.
22. Enforceable copyright
The record companies, film studios and news agencies are fighting back, but can the floodgates ever be closed?
23. Reading telegrams at weddings
Quoting from a wad of email printouts doesn't have the same magic.
Websites may have helped spread the word about dogging, but the internet offers a myriad of more convenient ways to organise no-strings sex with strangers. None of these involve spending the evening in lay-by near Aylesbury.
25. Aren't they dead? Aren't they gay?
Wikipedia allows us to confirm or disprove almost any celebrity rumour instantly. Only at festivals with no Wi-Fi signals can the gullible be tricked into believing that David Hasslehoff has passed away.
26. Holiday news ignorance
Glancing at the front pages after landing back at Heathrow used to be a thrilling experience had anyone died? Was the government still standing? Now it takes a stern soul to resist the temptation to check the headlines at least once while you're away.
27. Knowing telephone numbers off by heart
After typing the digits into your contacts book, you need never look at them again.
28. Respect for doctors and other professionals
The proliferation of health websites has undermined the status of GPs, whose diagnoses are now challenged by patients armed with printouts.
29. The mystery of foreign languages
Sites like Babelfish offer instant, good-enough translations of dozens of languages but kill their beauty and rhythm.
30. Geographical knowledge
With GPS systems spreading from cars to smartphones, knowing the way from A to B is a less prized skill. Just ask the London taxi drivers who spent years learning The Knowledge but are now undercut by minicabs.
We may attack governments for the spread of surveillance culture, but users of social media websites make more information about themselves available than Big Brother could ever hoped to obtain by covert means.
32. Chuck Norris's reputation
The absurdly heroic boasts on Chuck Norris Facts may be affectionate, but will anyone take him seriously again?
33. Pencil cricket
An old-fashioned schoolboy diversion swept away by the Stick Cricket behemoth
34. Mainstream media
The Seattle Post-Intelligencer and Rocky Mountain News in the US have already folded, and the UK's Observer may follow. Free news and the migration of advertising to the web threaten the basic business models of almost all media organisations.
What with tabbing between Gmail, Twitter, Facebook and Google News, it's a wonder anyone gets their work done. A disturbing trend captured by the wonderful XKCD webcomic.
36. Mr Alifi's dignity
Twenty years ago, if you were a Sudanese man who was forced to marry a goat after having sex with it, you'd take solace that news of your shame would be unlikely to spread beyond the neighbouring villages. Unfortunately for Mr Alifi, his indiscretion came in the digital age and became one of the first viral news stories.
37. Personal reinvention
How can you forge a new identity at university when your Facebook is plastered with photos of the "old" you?
38. Viktor Yanukovych
The Orange Revolution in Ukraine was organised by a cabal of students and young activists who exploited the power of the web to mobilise resistance against the old regime, and sweep Viktor Yushchenko to power.
39. The insurance ring-round
Their adverts may grate, but insurance comparison websites have killed one of the most tedious annual chores
40. Undiscovered artists
Posting paintings to deviantART and Flickr or poems to writebuzz could not be easier. So now the garret-dwellers have no excuses.
41. The usefulness of reference pages at the front of diaries
If anyone still digs out their diaries to check what time zone Lisbon is in, or how many litres there are to a gallon, we don't know them.
42. The nervous thrill of the reunion
You've spent the past five years tracking their weight-gain on Facebook, so meeting up with your first love doesn't pack the emotional punch it once did.
The original computer timewaster has been superseded by the more alluring temptations of the web. Ditto Minesweeper.
44. Trust in Nigerian businessmen and princes
Some gift horses should have their mouths very closely inspected.
45. Prostitute calling cards/ kerb crawling
Sex can be marketed more cheaply, safely and efficiently on the web than the street corner.
46. Staggered product/film releases
Companies are becoming increasingly draconian in their anti-piracy measure, but are finally beginning to appreciate that forcing British consumers to wait six months to hand over their money is not a smart business plan.
Made superfluous by the link, although Wikipedia is fighting a brave rearguard action.
48. Grand National trips to the bookmaker
Having a little flutter is much more fun when you don't have to wade though a shop of drunks and ne'er-do-wells
Blogs and fansites offer greater freedom and community interaction than paper fanzines, and can be read by many more people.
50. Your lunchbreak
Did you leave your desk today? Or snaffle a sandwich while sending a few personal emails and checking the price of a week in Istanbul?