I wrote a little paint/sketch program.
Here a first version
It has 3 modes: keyboard, stylus and Stylus-DragAndDrop(click for the startpoint and release for the endpoint of each line.)
To run, drag the "Drag" of the mode you selected and drop it to the "Drop" of "Drop here!".
To return to the mode-screen, press START.
To quit, turn the power off.

It doesn't support saving, but i hope i can add this feature (i dont know how).

Keyboard mode

Sorry for the many posts, but i dont have webspace and the files are too large.

Last image: Stylus DnD linedrawing