you cant rip the umd's as far as I know.
But you can convert dvd backups into the right format!!!
You could probably get 2 films on a one gig card I reckon!!!
or there is a 4 gig hard drive/battery combo thingy you can get!!!
like this...
http://cgi.ebay.co.uk/ws/eBayISAPI.d..._BIN_Stores_IT
I have the battery already!!!
I also have 7 series of only fools and horses on 2 dvd's in the correct format!!!!