Sweet. How coincidental - I was pondering exactly this the other day. I've been rewritting the old windows video-game Gazillionaire (http://www.lavamind.com/gaz.html) in Perl/Tk for my own amusement recently and I was thinking about how to do a fullscreen mode using just Tk. Between this and your other node on removing decorations, this is perfect!

$w->{main}->overrideredirect(1);
$w->{main}->geometry($w->{main}->screenwidth."x".$w->{main}->screenwid
+th."+0+0");
[download]

{NULE}
--
http://www.nule.org