Kill Spam Automatically

[america2]

I run a large forum and the amount of spam I get is mindboggling. Does anyone know of any mods that can help with this (i.e. a captcha, spam autodeletion script, etc.) Thanks!

[sybarites]

moderate all new users

[ThomasR]

moderate all first posts (use promotions to do that, it works great for me) and I know that CGtalk (a very laaarge vb forum) use this system too.