1script - 10:49 pm on Mar 28, 2010 (gmt 0)
Yeap, good idea. I'm doing it for a couple of years myself. Except I don't have a sacrificial site, I'm just sharing the banned users, emails and post subjects between all my sites. I would not overly rely on that though because there are great many angles spammers are working. Still need a pair (or several) of human eyes and even that fails to catch all 100%.