"Splogging?" Did you make that up?
Seriously, though. I'm just ribbin' ya.
IMHO a good method that could be used to keep splogging from spreading (here come the t-shirts) would be a word- and phrase-recognition system combined with a "black list" of offending IP addresses similar to those used by "spam filters" and web server anti-hacker programs. Not so tough to put in place. There's some automation plus the blog admins would look things over every once in a while and append/amend the filters.
A blogging application that cuts down on splog. Brilliant!
It sounds like a good point of ingress into the software market for an enterprising individual.