Another little project that I made some time ago but I forgot to mention: http://serhost.com/projects/captchatrader/.
You can also download it from github: https://github.com/jfsanchez/CaptchaTrader
CaptchaTrader.py is A VERY SIMPLE class written in python that resolves captchas using captchatrader.com web service. It is an example on how to consume web services in python.
I do not condone SPAM, there are several fair uses of this library that I can think of. If you try to use this for sending spam, better go to hell.
I have no relation with captchatrader.com except as a sporadic user.
UPDATE: CaptchaTrader service was closed shortly after I made this script.