Okay, so check it! I've gotten the intro to go "webstreaming" for quicktime off of iMOVIE HD...however it's so flippin' small that the experience is ruined. WHAT DO I DO?!

Thread moved.

You should have the option to adjust your movie render settings. I am not familiar with iMovie, but I'm sure someone on the site can advise you where to find the option to change the movie output size. Or, check the manual / help screen for "render settings".