Free resources on the Web

It just amazes me on the availability of information on the web. For a brief timeline of the "internet" see this link:
http://www.webopedia.com/quick_ref/timeline.asp

When I was a grad student in the eighties, we had email. And we could connect to other computers via FTP. And I would spend hours exploring (exploring wasn't coined until the 1990s) the networks trying to find environmental data like satellite imagery. It was all free back then, and for the most part, it still is. Just try "googling" free satellite imagery to see what you can get (besides Google Earth).

Enjoy!