http://www.speedtest.net/
Tests internet download and upload speed of your connection.
I'm downloading at 27.13 MB/s, and uploading at 0.97 MB/s, which according to them is way better than the average ISP.
I don't know enough about this stuff for it to be meaningful to me, but it's kinda fun, and I figure the more I play with it and discuss it, the more I'll understand.