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
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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.