There are someinteresting articles that I would like to point the AO community to.
They are about Tarpits. I could give a shot off explaining the concept but I think the articles do a better job then I will do:
Here are the links:
A 'Tarpit' That Traps Worms <--wired
Slow Down Internet Worms With Tarpits <--security focus

If more people would join in this concept I think the worms could be slowed down big time.
Please read the articles !
Both are a bit outdated (one from 2001) but I still think they are a good read.