I found this example at Win32::GuiTest::Examples called showmouse.pl. It didn't work at first until I either added $|++ or printed to STDERR.

#!/usr/bin/perl
# This script has been written by Jarek Jurasz jurasz@imb.uni-karlsruh
+e.de
#$|++;  ## use this if you don't want to use STDERR
use Win32::GuiTest qw(GetCursorPos);
while (1)
    {
      my ($x, $y) = GetCursorPos();
      print STDERR "\rx:$x  y:$y   -";
      sleep 1;
    }
[download]