Ultra Mobile Personal Computers are really good. Chris has a Samsung Q1 Ultra with an OEM HSDPA card making it a very portable computer / a very large phone.
The 7" screen is good enough for general surfing, reading and note taking. What really surprises is the fact that the 800MHz processor with 2GB RAM is enough to run Vista Aero interface. And its not sluggish either. I managed to use LogMeIn to remotely connect to my home desktop over HSDPA without any trouble at all. Despite the sluggish ping time of 130ms and slower 1Mbps sync speed (up to 6.3Mbps in T-Mobile UK Nov-2007), the response was really good and totally useable. MSN webcam video call struggled a bit at 2fps though.
I'm now thinking about getting the Asus EEE PC when the 8GB version comes out. I can't find a decent smart phone and this mini-laptop is a bargain at £220 RRP for what it does. It would pair up nicely with my old K800i (no HSDPA though).