Alexa.com measures web traffic. Are there any others like it?

Answer 1

Keep in mind that alexa is only tracking people that use their toolbar, so it's a slice of real traffic, not representative of the whole internet. You can get Google Analytics set up on your site (for free), it will track all traffic to your site, and where it came from, etc.

The links below will show you your Google PageRank, and who links to you. (not traffic numbers but will be an indicator of how easy it is to find your site)

Answer 2

hitslink.com