Just a note, but you can grab a free legal copy of Max if you're a student at the Autodesk Education website.
This is new, what's the limitations on it?
You must be one of the following: (a) a faculty member; or (b) a student; or (c) an Autodesk Assistance Program participant.
But other than that, it's the full program. The license lasts for a year, at which point you need to request a new one (it's easy though, just push a button).
Also, they state that you're only allowed one license per user per program, but I've successfully activated multiple installs. Oh, and this applies to basically every Autodesk program in existance as well, not just max.
ontopic:
Hmm. Something like a gravity missile, or a missile that plays with the physics of the target would be interesting. Scripting?