Automated forum account creation/posting, blog comment spamming, craigslist account creation/posting to name a few.
Some other famous sites that are doing this since the mid 2000s - http://decaptcher.com
They integrate with just about every famous spam tool.
UPDATE: Automated Gmail, Yahoo, Hotmail account creation, etc. They create accounts in bulk and then spam through the gmail, yahoo, and hotmail accounts by tools that are being sold.