There are a number of threads that discussed theoretical ways and some other attempts to print from 770/N800's. Try searching on a word like "printing". Here are some examples (not too promising, near term):
http://www.internettablettalk.com/fo...ead.php?t=3911
http://www.internettablettalk.com/fo...ead.php?t=6537
http://www.internettablettalk.com/fo...ead.php?t=6269