Heh, well when the school i attend merged with another school that more specialised in embedded systems they used this board exclusivly: http://www.ibutton.com/TINI/hardware/index.html
Our teachers where interested in integrating this device into our current "embedded systems" curriculum. After some toying around with the teachers, the same conclusion came up when we dealed with java on an PC. Its slow. One assignment the school gave us for this board was attaching an VS1001 chip (an chip capable of playing MP3 sound) and play some mp3 music. And it did that but no higher bitrate 128kbps, otherwise skips in the sound. When you pressed a button on the keypad, the sound skipped or a blip sound was audible.

But the main reason the teachers did not want this device as it used java as its main language, it would interefere with the current curriculum that was almost C sprinkled with bits of assembler. It just isolated you too much from the device itself. Not something you want when learning embedded systems.