I'm having a lot of trouble using mencoder to create videos that can be played back with quicktime on a mac. Ive tried a number of audio/video codecs without much luck. One problem is that, since I don't own a mac, I have to go to the university comp labs just to test the video out so it's quite annoying when the video doesn't work. Here is what I have tried:

Audio codecs:
mp2/mp3: qt complains that it can't find the necessary software
aac: i can't seem to generate aac files (with faac) that play on mplayer. If I can't even get them to work on mplayer, I'm not so keen to ride to uni to test tham out on qt.
wav: works! but the file sizes are HUGE

Video codecs:
libavcodec h263 and h263p: plays fine on mplayer, but qt says that the file is corrupted and the video doesn't display
libavcodec mpeg4: qt complains that it can't find the necessary software
libavcodec msmpeg: qt complains that it can't find the necessary software
xvid: qt compains that it can't find the necessary software
divx4: qt complains that it can't find the necessary software

I couldn't find any FOSS Sorenson3 encoder; there's an encoder for Sorenson1, but that isn't listed on apple's website as compatible with qt. Any suggestions for other codecs to try (or how I can get aac to work--mplayer was compiled with aac support)?

FWIW, I'm using .avi files rather than .mov because mplayer crashes on .movs.

TIA