Certainly, many people have to have a laptop, for travel or whatever. However, it's worth considering whether it's needed or not. If all you do with it is work in a couple of locations, especially if one of them is home and you already have a machine there, a laptop may not be the best solution.
Laptops are more expensive, much less expandable, have small screens and cruddy keyboards. Even the lightest ones are much heavier and bulkier than carrying around just a drive or flash drive. So if you don't NEED one, it's probably worth thinking about not having one.