If you are making a game you could use something like http://unity3d.com/ which allows you to package it for Windows, Mac OS X and web based play all from the one Mac OS X development environment. I think a 30 day trial is available.
Hey, thanks for that link. At my district we use Alice for game design classes... it's free but I don't mind spending dough on something THIS good looking. How popular do you think it would be for the students to make iPod and iPhone apps? Holy cow, I'll be a hero!