OK so you have bought an Acer Aspire one with just 512MB of memory and you want to upgrade it to 1.5GB. You've looked on the net and seen the youtube videos and you are worried about screwing up your machine and voiding your warranty.
PC World offer a memory installation service for £14.99. Now normally this involves undoing 3 screws and clipping the memory into a slot - a 1 minute job - even for laptops you usually open up a compartment and slot in the memory. Easy money for PC world.
However the AA1 requires you to undo a lot of screws, remove ribbon cable, remove the keyboard and crack open the case - a half hour job with the potential to break the machine. PC world will however do this for the same £14.99 they charge to install memory on a desktop - a comparative bargain.
I know someone who has had this done at PC world to their AA1 and they did a great job - obviously their reputation goes before them however YMMV. At least if they trash it they sell new ones so they should be able to compensate you then and there!!!
You have to buy your memory from PC world but they do a 1 GB SODIMM for £13 (Product code: 926560) which is a similar price to Crucial.
Note: if you have the 1GB version you already have a 512MB SODIMM in the slot so you will still only get 1.5GB total