I threw some AdSense ads on my site the other day. I don't think I'll be getting rich any time soon though. I'm up to 58 cents so I figure I'll be seeing a check from Google in about 8 years. :)
Anyway, while troubleshooting an error in my blogCFC I noticed I kept getting each error E-mail three times. Looking at the User Agent showed that "Mediapartners-Google" was hitting every URL I hit twice. Incidentally, I have two Google ads on every page of my site.