Plus, with a laptop, you can rip your DVDs into MPEG-form and play them from your laptop's hard drive. Saves on battery usage (continuous useage of the DVD drive drains the battery like crazy), you don't have to carry DVDs around (keeping scratches to a minimum), and when you're done watching the movie on the trip, you can delete it.

Movies rip to about 400-500MB for high-quality full-laptop screen viewing, so you can have about 20 movies in 10GB of space. The only disadvantage is that you won't be able to view any of the special features (i.e., commentaries, which is what I really buy DVDs for).