iMovie HD 6 has a great new—but subtle—feature. In earlier versions, if you wanted to add a title to the middle of a clip, you needed to first position your playhead, choose Split Clip at Playhead from the Edit menu, and then drag a title to that location. In the new version, simply position the playhead and click the Add button in the Titles pane; iMovie does the clip splitting for you.
(You can tell that I’m working on an iMovie book update, because I start posting items like this as I find them. For other iMovie HD and iDVD tips I’ve posted, you can view them in the Tips category.)