AMCNUTHe has a Blackberry - that's punishment enough!
Nah, I jest - I like Blackberry, which is good because I own one! But as to how to crash one - I've never tried. Maybe just send lots of texts to annoy him or something, or try to hide his phone somewhere? Besiege his phone so that he can't effectively use it because of all your texts!
How dedicated are you to revenge?
Seduce his girlfriend.
Phone language to Russian (there are alot of people who can read Chinese), change all the numbers of his contacts into his mum's number, get his mum's number and send her a message saying something incriminating about him, change his screenlocks, post statuses and messages on Facebook from his phone (most people leave themselves logged in), factory reset, or take out the vowels from his keyboard on his phone (if there is one).
Get better friends? Not a single one of my friends would ever do that because I don't tend to hang around with jerks.
Two words... Cat Facts.
AUPYou will not behave in an abusive and/or hateful manner, and will not harass, threaten, nor attack any individual or any group.