Long-time readers may have noticed that spam on the wiki has been a very persistent problem for the past 2 years or so; I've been dealing with it so far by hand, but I recently reached a breaking point and asked Trike to resolve it or find a new wiki administrator. (Speaking of which, is anyone interested?)
So Trike has enabled a MediaWiki extension called the edit filter: a small functional programming language which lets you define predicates applied to edits which trigger one of a set of actions, like banning a user, deleting an edit/page, or stopping an edit from going through. I have so far defined one rule: page creation is forbidden for users younger than 24 hours. This so far seems to have worked well; spam pages have fallen from 5-10/day to ~5 over the past 2 weeks. This is much more manageable, and I am hopeful that this new anti-spam measure will be effective longer than the previous additions did (but if it doesn't, I'll look into adding more rules dealing with images and external links, and perhaps also ban users whose names end in a numeric digit as almost all the spam accounts do).
If you've run into this edit filter before by making a page and seeing the submission rejected with an error message, fret not: merely wait 24 hours. (If your account is more than a day old and you're still getting errors, please contact me or Trike.)