I came across this site and it was awesome to use it. The main service for the users it gives is - search the web pages archive for a site from it's beginning to till date. I did it for google.com and i was able to view the first design home page of google which was in wayback 1998 !
I did a search for archive pages for the following sites -
* yahoo.com - check out how funny it is in 1996 archive
* msn.com - this also
It's a great site and worth of visit to it.