Ever heard about the waybackmachine? I don’t think you could call that Web2.0 or even innovative but still, it’s probably the most awesome Internet website/service I have ever seen: Archive.org is a website and a database which keeps track of all the various versions of almost every website that ever populated the Internet.
Archive.org, the Waybackmachine is the memory of the Internet
The so-called “Waybackmachine” can take you back to – for instance – the earliest versions of eBay. (see that version of January 1999 for instance). Unfortunately, it isn’t easy to move back more than 6 years, but still, it’s awe-inspiring, and useful too.
If you want to keep track of old content which has been wiped out of the Web. For my readers, I can also recommend the various versions of Visionarymarketing.com since 1998 (unfortunately, the earlier 1996 versions have not been stored).