in recent times, due mostly to steve jobs WONDERFUL yet TERRIBLE decision to move mac over to intel processor's, macs have been able to easily and efficiently run windows using bootcamp or parallels. and, like many things, if it goes one way, it can go the other way too. (insert bi joke here) such is true with windows, as it is possible to run leopard(it seriously took me forever to remember how to spell this), though it is impractical, very difficult (apparently) and has a high likely hood of crashing. so basically you could, if you REALLY wanted to, and were really good at computer stuff, run imovie on a PC. im sure there's other ways too, but basically for you its impossible.
the hackintosh has been around for a long time, but it isn't a practical solution and the only reason to do it is to show someone that you can do it. And it is pretty hard to criticize the decision to move to intel when you look at how mac's have been selling. Seems having the "what if" option of still running windows was enough to push lots of people to the mac, especially younger people who may need the odd windows program for school.