Hello Trisha,
I have a MacBook Pro 17", and ended up buying an iPad to bring along on my numerous trips.
When I'm on a plane or train, I bring my iPad instead. At first I thought this was a way better deal, and that I would only bring my MBP to meetings within the same city or while driving to another nearby city (I live in Montreal but work in Ottawa).
Having said that, I now tend to bring the iPad even on short road trips too, instead of the MBP. With all my important files on MobileMe iDisk, I can just access them from the iPad anywhere anyways.
So now I only travel with the iPad, but of course I still use my MBP 90% of the time at home or in coffee houses (I like to work from the local Starbucks on a daily basis).
Nothing replaces a real computer with OS X (
yet), but the iPad is soooo convenient...
My two cents.
Dr Sly