ipod help for a weary traveler

I'm going to be stuck in airports a lot for the next 2 weeks. If I get something like a 40gig ipod video(used for $100), how many movies will it hold? How long will the battery last too? Can I rip dvd's straight to itunes.
Thanks, Emery
Correct me if I am wrong, but I don't think you can (legally) rip dvd's into iTunes unless the dvd has a digital copy like many new releases are coming with lately. I only have two movies that I ripped to iTunes via the digital copy (The Dark Knight and Incredible Hulk) and both are under 2 gigs each to give you an idea of capacity.
look at slysoft.com for software...

watching movies on that screen may get a little tiring.. and video battery life on the older ipods isn't so good

consider an Ipod touch. You can also access the wifi network at the airport with the touch.
Thanks. I'll check things out.