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

I've succesfully used hashcash before.

It requires a javascript enabled browser and delays the post by a few seconds (configurable), but has the advantage of not adding UI complexity.

While hashcash doesn't avoid spam per se, it requires the spammer to waste time computing javascript hashes, which in turns requires that the spammer has javascript enabled (which is quite rare), and that it cannot do more than few spams per minute