I have a Sony Vaio. It’s very lightweight (around 3 pounds).
The CD and floppy drives are external. Since I don’t use them much, I leave them at home.
It does have a memory stick port. If you’re thinking of getting a digital camera you might look at the Sony Cyber-shot (DSC-P1). They work great together. Just unplug the memory stick from the camera and plug it into the computer. I love it.
Ditto on Slasher’s list but skip the lock and chain if your homeowners insurance covers items that go missing form hotel rooms.
Oh, if you put the laptop in your suitcase, don’t forget to wrap it in a plastic bag. I had a shampoo bottle leak.