What can be done to prevent spam in forum-like apps?

Question

Are there ways except CAPTCHAs for web apps like pastie.org or p.ramaze.net? CAPTCHAs take too long for a small paste for my taste.

Answer 1

from wikipedia

A CAPTCHA system is a means of automatically generating new challenges which:

* Current software is unable to solve accurately.
* Most humans can solve.
* Does not rely on the type of CAPTCHA being new to the attacker.

I my self am really bad at resolving Captchas (at least the image based ones) and to me it feels like the current implementations do not fill the "specification" above. A lot of the widely used implementations can in fact be solved with software. I'm like most humans and I can't solve these... (subjective I know)

I would probably try implement a system where users can mark stuff as spam those would me removed. Yes the spam would be visible but not for long without any input from admin himself.

Come to think of it the reputation and voting system here at SO quite effectively reduces the impact from spam as questions get closed and voted down => lover visibility