And you could optimize what you send over the serial by stealing the VNC code that generates rectangles of data to update and only sending updates for them to the display instead of the whole 128x32.

I'm doing a similar thing but with different goals (visibility in the sun and keeping Empeg in the trunk so I don't have to take it out every time I leave my convertible). Noritake has a nice 140x32 display that's 115.2kbps, and a 256x64 that's unfortunately only 38.4 (by serial.. parallel is faster). Haven't decided which to use yet. With the extra space extra apps could be made to run and not cover up the Player display (or on the 256 one it could be pixel doubled to show the Player fullscreen).

This might also be of interest to you.. Grayhill makes a joystick that has an optical encoder and pushbutton all in one knob. I'm planning on using one and converting my cigarette lighter into all 7 functions on the Empeg face, except that I haven't found any place to buy one yet.