HOWTO Get 400 x 800 resolution
Gary McKinney did some more research to get a 800 x 480 LCD display working with the Palo43 expansion board and an Overo COM. He posted the information on one of his blogs about the display and what is needed to get it working with the Palo-43 LCD interface board here.
According to Gary, the modifications to get it working are VERY MINIMAL and he ended up with a display with about 4X the resolution than offered with the 4.3" LCD display Gumstix sells. The price difference is about 15 Dollars (US) counting the postage for shipping!
"Now, instead of a 480 X 272 LCD display I have a 800 X 480 Display (4X more display info) so can now do many more things with the computer system (better, fine-resolution graphics comes to mind)".