T-mobile UK offer unlimited mobile data for £7.50 a month (on top of your normal call plan), which I think is pretty good value. It's why I chose them when I got my Nokia N95 - there wouldn't be much point in having that phone if I couldn't use the internet on it without worrying about data charges.

You're right about the roaming data charges though!

I have a M-Audio Audiophile 2496 PCI card and have never had any problems with drivers, it works great in WinXP and Linux (using ALSA) and comes with a good mixer utility.

The only problem I have with the card is that there is no gain control on the inputs so you have to make sure that the input signal is the correct level some other way (e.g. by using an external mixer). Then again it is a pretty basic card and M-Audio make plenty of more advanced ones.