Actually I've just finished a couple for an advanced Perl class that I took.
in reply to Perl Desktop Applications
The first one I've now seen a couple variations of - Regular Expression Trainer. I wrote it in Perl/Tk as a homework assignment.
The other one is an image map utility. It allows you to take a graphic, select the image boundries on where you want to have your image map locations ( with little red dots so you can see where you clicked ) and upon completion, writes the image map code to a text file.
Both these are going to be posted to Cool Uses ( hopefully this weekend ) as soon as I do a couple of minor tweaks.