Modem
If I could use this as a modem I'd definitely get one as I have to carry a laptop around with me everywhere I go when I'm on call as I manage servers.
However for now until I can see an easy way to hack it to work as a reliable modem I'll have to stick with my HTC Touch Plus on T-Mob W&W.
I think the Xperia will be my next phone purely because iPhone doesn't have modem capability, the touch was just a filler until something better came out as my Nokia N95 had crappy battery life and can't recharge via USB so was pretty useless.
I hate all this fanboy stuff, it really is pathetic - if something does what I need it to do then I'll get it.