Since 99,9% of the spam comments on Spreeblick seem to carry a yahoo.com mail address, I blocked all entries from those accounts. Sorry for the inconvenience if you are an honest reader commenting from yahoo. Blame it on the spammers.
Update: Due to the asshole that posted 12 spam comments last night, I added hotmail.com accounts as well. Hotmail sucks anyway, so if you’re using it: Dont’t.
Though it is pretty easy to de-spam MovableType (as long as I still use it) with MT-Blacklist, I will keep blocking whole mega-providers as long as they don’t find a way to keep out spammers.