I've been using perl/TK, although I like tcl/tk too, I still think Perl/TK is a bit easier to write, although it's not perhaps as portable, but I like it. I used that for a benchmarking program where you chose the options from the GUI and then start the main program, although it could have been done with command-line options, I felt that I had too many options and chose another approach to that current problem. In any case I would encourage the use of perlTK.