MiniMail made me want to have something like that for iCal, too. Here’s an idea of what it could look like, incorporating the layout of the iPhone’s calendar list view:

Ideally, it would show To Do items in another pane, perhaps a pane above the appointments list. I didn’t mock that up yet.

If I were further along the path to Mac development proficiency, I’d do it myself. One thing I thought of, though, was that iCal might not support plugins like Mail.app does, and any plugins it did support might break in Leopard. InputManagers would for sure. Maybe, then, this should be an APE haxie.

I’ll let the LazyWeb sort it out for now.