Keynav provides the alternative way to control the pointer for people who have troubles with nubs and/or touchscreen. It can be used right after installing, restart is not required.

Here are some basic keys:

F1 - activate
Esc - abort
D-PAD - move cursor
Space - click
Enter - double click
1,2,3 - click with a specific mouse button
P - move pointer without clicking
L - toggle dragging
W - move the pointer to the center of the active window

Space, Enter, Esc and P will quit keynav mode, other keys will not.

Keynav can be configured by editing .keynavrc file in your home directory. The executable will be installed on NAND, so the PND can be removed after installation.