Spotlight on: the Internet Archive
An invaluable and £-free resource for the academically interested.
A very special internet site for any library enthusiast: The Internet Archive (IA). It "was founded to build an Internet library, with the purpose of offering permanent access for researchers, historians, and scholars to historical collections that exist in digital format." Access to their digital resources is free: for everyone! Resources include text files in various formats (pdf, html, txt), live recordings, audio and video files.The front page features random selections from all categories: at my last access I stumbled on a live recording of a 1977 Grateful Dead concert, an aurally challenging "Pax Futile" by Seikkailuja Ahkymaassa and a 19th Century children's book called "Letters from my cat". Some books have been uploaded as "flip books", featuring a visually pleasing simulation of flicking through the pages of a book which is at the same time searchable. Most importantly, the IA gives you free access to books of which your own library might only stock a few physical copies. For example, Herbert Marcuse's Soviet Marxism is freely available in various formats, including flipbook and downloadable pdf. So if the copy in the library has already been taken out, get your own here: http://snipurl.com/9oona.
Finally, the IA features the "Wayback machine", with which you can search webpages they way they once were, all the way back to 1996. Not everyone agrees that the IA has a "right" to archive pages whose authors or owners no longer display them, but in their own words "the Internet Archive is working to prevent the Internet - a new medium with major historical significance - and other "born-digital" materials from disappearing into the past."
Whatever your stance on this issue - the IA is treasure trove of online library treats and well worth your visit.