I have Quicktime Pro, but it's not my choice for converting .mov files to other formats.
I use a program called tmpgenc. It's primarily intended as a mpg editing app, but it can also convert from other formats into mpg. To convert .mov to mpg, in addition to installing the app itself, you also have to find a file called QTreader.zip, which is a quicktime plugin. Unzip the plugin into the tmpgenc directory. It makes excellent conversions to .mpg format. It can do mpeg1 and mpeg2. Use the mpeg2 for very high quality, the mpeg1 for the usual stuff. If you never register it, it stops letting you do the mpeg2 after a while.
The mpg files are larger than the corresponding .mov's, but I prefer the mpg format so I don't really care about that.
ps - the app is easy to find, but if you can't find the plugin (it's probably on their site, can't remember), pm me with your email.
I am the Cheese. I am the best character on this show. I am better than both the salami and the baloney combined.