I'm just in the middle of upgrading from Movable Type, and there's a plugin I sorely need. If anyone know if this has been created, please let me know.
Basically, it's a disemvoweler for comments. Any post that comes from a specific IP address gets all its vowels removed before displaying. :)
In the past, this feature has worked like a charm in keeping the trolls permanently away, and I would hate for all my disemvoweled comments to re-appear when I officially switch over the WP.