About three weeks ago I reopened comments here, after a lengthy spam induced hiatus. It took only 5 days before someone did the first manual spam entry to fight my new anti-spam solution, and now two weeks after that the first automated attack against my static checkcipher was implemented as I got hit by roughly 1000 hits of auto-spam, complete with correct checkcipher.
I've now changed the checkcipher. Next benchmark will be how soon before someone catches on to that. If that is less than three weeks I'll have to do actual captchas.

[UPDATE Nov. 14 : It lasted one day. Does the guy keeping up not realize that his comments are not getting published on my weblog, because I audit everything? Now I've changed it again. I wouldn't call this exercise fun, but interesting at least. It seems I'll be going full on turing test in only a few days]