I keep reading about Sony's free classics offer (100 books, I think?) with the purchase of the Sony Reader. Is this only for purchases made through Sony's own websites, or something tied to the activation/registration of the Sony Reader no matter where it was bought from?

Mine were on a cd/dvd included in the box with my 505 (bought in UK so maybe different in other regions?).

It was bought from a Sony shop originally, but I think others who bought from Waterstones have also had this in the box.

You can buy the Sony anywhere and get the classics, the promo is tied into actually registering the device.

You can also get them here, free and without DRM. I tend to get the Sony Classic one first though, since I have grown fond of the giant margins (the ones on here have smaller ones). But the ones on here have a lot less errors.

What were on the CD, ruth? The 100 eBook classics themselves, or some sort of activation code for downloading them from Sony's store?

Never mind. It's all clear now. ;)

If any one else needed to know, the actual books were on the cd. As lilac_jive says, they're also available on this site as they're classic books.