Pretty niche, this one, but I think it's a great deal.
Most people who work in IT will know that O'Reilly books are very expensive. I'm sat at my desk looking at a 'Learning Java' book that cost me the thick end of £30.
Well, whilst browsing the app store on my iPhone I found that O'Reilly have bundled a load of their books up in the Stanza ebook reader app and are selling each title for peanuts (£2.99 seems to be the most common price point). That 'Learning Java' book I paid £28 for? £2.99.
Trying to buy the equivalent ebook in the Stanza O'Reilly store will cost around $30 each, so I'm not quite sure what they're up to here, but I intend to fill my boots.
Just to be clear, these are eBooks only - you read them on your iPhone, you can bookmark them and search them. As far as I can tell, it's the entire text, and in digital form these things are a lot lighter to carry.
You can always check the ratings in Amazon to see if a title is worth having before pressing the button, but (depending on your connection) you could then be reading the book within a couple of minutes.
Hope somebody finds this useful!