Hey Chris, bugger the 350 (I gave in and bought another one from BestBuy, my son's never giving my first one back !) or the 650 - I managed to lose the T1 stylus in 7 minutes !
So I'd do a bit of research re: dimensions !
On second thoughts, don't, just flatten the 6/350 one,colour it black and youm away - 'cos there's no place to dock the thing anyway, so you could make it any size you like.
Even put a funny head on it ? Or something a bit more risque, perhaps, for the butch male market ?
I can't see I'm gonna be the only one not to lose the bloody thing !