I might go with a more active toolkit for joystick, like maybe gtk+ joystick lib. No one has done it yet, but it may be a good candidate for a Perl module to access the lib. Then conceivably the joystick actions would become part of the PerlGtk bindings. (I would go to the Perl/Gtk2 maillist and ask/beg :-) )

As long as you can get the joystick to show up in /dev/input as /dev/js0 ( or something similar), you could use Perl to read the device and translate it's binding to something Tk uses.

</brainstorm>