LooksBack
See old screenshots of websites and software as they were. Oldest first.
Try:
Facebook
Winamp
Xfire
MySpace
AIM
ICQ
Napster
Geocities
Netscape
Friendster
MSN Messenger
Bebo
Habbo
Newgrounds
Kazaa
LimeWire
Wayback Machine
Screenshot snapshots of websites year by year since 1996.
Internet Archive
Old software, programs, games and digital collections.
Wikimedia Commons
Historical interface screenshots and logos.