Chatalog is a new application from Freeverse Software which archives iChat logs in, of all places, your email program. While it may seem odd at first, storing messages in Mail (or any other Mail program) makes searching your iChat history very easy, making use of Spotlight to quickly find what you’re looking for. You can also apply Mail rules for even finer-tuned sorting and labeling. Chatalog is a great little application for keeping things organized, and I’m sure I’ll be registering it in the near future. [via] (I suggest disabling Spotlight searching of your iChat archive folder (in System Preferences) so you don’t end up with duplicate results if you use the system-wide Spotlight icon to search for chats.)
Update: I’ve switched to Chat Transcript Manager. It’s a separate application, so it works differently than Chatalog, but it meets my needs better. Definitely worth a look.