After (what seems as) zillions of spam messages, the solution is near: The death of all spammers.
The killing process is fairly easy: Let the spammers use their hardware on sending spams, but make sure you got mechanisms to stop them.
On Email-spams, one solution is described by Peter Hansteen: Use packet filters in combination with several simple spam identification mechanisms. This makes (among other things) a huge tar pit to let the spammers slide into.
On BLOGs like this, you can use Akismet in combination with the .htaccess extension to block the most aggressive spammers. Akismet itself can be fooled by the most aggressive spammers but personally I found that when I blocked some American IP-ranges, the spamming question got a bit more in control.