iMovie HD (06) has a nice little function that splits the video clip at any point you want.

With iMovie 08 there is very little reason you would want to split the clip, so the oh-eight doesn’t have this option. But if you really want to do it, there is a way around. The entire work is done in the event pane, the lower half of the screen.

Here is a clip that we want to split in two.

First, we need to spread the clip wide in order to enhance the selection precision, so in the lower right corner of the screen you need to select 2 sec or shorter time.

Now we click on the clip where we’d like to split it…

…then click and drag one side of the selector towards the other so we actually select the shortest possible time, e.g. 0.1 sec.

Right clicking the selection gives us the contextual menu, so we select Reject Selection

Dropping only one frame results in the clip being split in two.

Simple as that.