Back in 1998 part of my TAFE Multimedia course was to combine live action footage, 3D animation, sound and 2D animation into a movie of at least 40 seconds, and no more than 20 megabytes. This was my rather strange effort. The original was 19 megs in size, 320x240 screen size, and had good quality vision and sound. Sadly it only plays on Macs (that's Quicktime for you) so I haven't seen it in years.
This version weighs in at 1.28 megs. I mercilessly crunched it down to fit it onto a floppy, so the frame rate and sound are abominable. But at least it shouldn't take too long to download. Be warned! The sound is LOUD (better turn off your speaker amps or risk a heart attack when it finally downloads. I'm not kidding).