Sometimes I poke around in the Vegas forum.. and this is something that works in Vegas Studio too that I thought was really cool.

"Wow! This is amazing! I took an animated GIF (Microsoft Clip Art)
of a butterfly flapping it's wings and placed it on the Vegas timeline.
With a little bit of keying I got it to fly around the screen!

TOTALLY AMAZING!!!!!!!!

Try It!"

(just go to Microsoft Clipart website and download a few animated cartoons with transparent backgrounds, put them on your timeline, and have fun.