I have been taking my laptop any time I go to Florida. I use it for downloading and processing my pics, but also for getting on the net, and sometimes as a giant MP3 player, since I have ALL of my digital music on the laptop but can only fit a fraction of it on my MP3 player and its MicroSD cards.
But on shorter trips where I leave the laptop at home, I carry memory cards large enough to fit one heavy shooting days worth of pics, and have 1 for each day of the trip, plus a spare. For me, this means 1gb cards, since a 1gb card will hold about 250-300 pics on my camera's highest quality settings, and I rarely shoot more than 250 pics in a single day.
At the end of each day, I put the used cards, full or not, in my hotel safe, and put a fresh, empty card in my camera. This way, if something happens to my camera or one of my cards, I can never lose more than one days pics; I'll never lose the whole trip.
When I have my laptop with me, I download my pics every night and rotate the memory cards, and I burn a DVD of the whole trip's pics before I go home. The DVD acts as a backup in case something happens to my laptop; it goes in my checked bag on the way home, not in the laptop or camera case.