I got my Blackberry in high school- it is very useful. It has all the stuff kids our age need and much more on a phone; pictures, movies, music, full internet, 3G data speed (on Verizon and Sprint), GPS, push e-mail, and a full keyboard.
Maybe just a more basic phone like a Motorola razor, or a sidekick. The blackberry pearl is more designed for business use with full email capability, etc. The extra features mean the phone costs more and they aren't of much use to a high school kid.