I know that you probably think BT is an amazing thing, as do I.
A presentation at a college would be nice, but if you just skim the surface you will just be saying "Look at my GUI! I can customize it."
It wouldn't be a bad idea to show them a regular linux distro (not stripped down, with hardly any manual pages as an example).
Backtrack is a penetration-tester CD, so how are you going to show them BT if you don't plan on hacking? Show all of the basic applications that Windows can support, as well?
Just my spoof on that one, skimming the surface would be a 1 minute presentation in my eyes...