I love my Vaio. I have an SZ (13-inches, right around 4 lbs). It's considered an ultra-portable, but if I really had to tote it all the time I'd probably go for the TZ, which has an 11-inch screen and is under 3 lbs. They now come with an option for a flash memory drive, so they're super stable, and the screens are gorgeous - exactly what one would expect from Sony. They're a bit on the pricey side though - between 2-3k, although I haven't checked in a while so the prices may have dropped.

DH is a Mac guy, but I think my Vaio may have converted him. He wants the TZ as his next machine. I have to say when I replace this one I'll be going for another Vaio.