I have added a search box to the top of the sidebar on every page. It currently will do a search of tasks, checklists, bugs, milestones, and messages that match any of the terms in the search query. It does not do a great job of ranking the results; however, I feel that it does what it needs to do.

I was planning to add an advanced search function with a lot of options, but now I’m not sure if that’s really even necessary or not.