I use Tcl/Tk from time to time and it always seems the easy choice when I need a simple GUI and also need to make an executable for Windows (which is trivial with Freewrap).

Some of the things I've written are: a simple standby order input app, a Forms/Reports compiler (sends file to server, waits for response and informs user), and a Ghostscript wrapper for merging lots of PDFs into one file.