Question about iMovie ~ Zoom/crop ?

[ferdalump.livejournal.com]

Hey all! I am a fairly new vidder (started last December) and have a few vids under my belt. I work off of a mac and use iMovie. I have purchased a few Slick plug ins that gave me some more transitions and titles and such, but I am curious if anyone has experience with iMovie who could tell me how one might zoom in on a scene or crop a scene.

Any help would be greatly appreciated. Thanks so much in advance. :)