One thing that could help is iRig for the iPad, iPhone or iPod touch -
http://www.ikmultimedia.com/irig/features/
It's not "teaching" but it's a very cool toy and will definitely encourage the "not so disciplined" to play more.
It could also be used to educate students about various effects and amps - possibly helping them find a setup that works for them in a virtual world before committing to spending cash on the real deal.
(this post comes to you courtesy of my Macbook running Snow Leopard - so there may some bias towards Apple ? )