Took my Macbook Pro to Vegas and back in May. Rain, hail, snow, desert heat, etc.
Put it in a neoprene padded slipcase and sandwiched it between my clothes.
I've carried my Dell Vostro in the "Pizza Box" on rides up to 3,000 miles round trip. I put it in its case and wrapped it with a towel I carried in case of rain or whatever. I used it to upload files from my cameras and to stay in touch w/the folks back home at night via skype. Doesn't seem to mind the trip at all.
I have a Acer Netbook, its as small as a book, has wifi and does everything I need, mostly web and email. Use it to make reservations for motels. Would take a trip with out it