I rock a Panasonic CF-T2. Touchscreen, tiny, durable as hell and not bad spec wise. (I run Ubuntu.) I ran XP for a year, but it just got too bloated. (Should mention XP in VMWare under Linux runs better than any XP installation I've ever used.) The older models Panasonic Semi-Ruggeds pretty damn cheap on eBay, worth every penny. (Just make sure you look at the Semi-Rugged, not the Military grade suitcase laptops.) I'm sure there's updated models that have better specs if you need to push Vista.
I've had Sony's, Dell's, Compaq's etc. Sony Vaio's are friggin' gorgeous, but they're not to travel ready. Every Vaio I've ever had seems like its a laptop that's suppose to just stay in one spot. The more you move it, the more it starts to fall apart. The Dell Latitude line is pretty solid.
Why no Mac?