when I'm on the move, and after much searching I found what is almost the perfect combination. I also have a T-Mobile contract, and pay £30.64 plus VAT for a monthly allowance of £200 to use in whichever way I like.
I use a T-Mobile G1, which is the best phone I've ever had (better by miles than my previous Blackberry), and have constant access to email and internet. It's the perfect package for me, and works flawlessly - mail is pushed to the phone at whatever intervals I choose from each of my three mailboxes.
I also use a netbook with a T-Mobile mobile broadband deal, which costs me an additional £12 a month. Internet access is available anywhere there's a phone signal, although I'm less than impressed with the speed, in fact I've just written to T-Mobile to warn them that unless they turn up the throttle considerably I'll be leaving them at the end of the current contract. In a recent survey of Mobile broadband services T-Mobile came bottom of the list for speed, although all the network providers were slammed for not providing anything like the advertised speeds.