actually jon, gnome is itself a toolkit for GUIs. GNU Network Object Model Environment to be exact. TCL/TK must be written together too, because TK is just based on the programming language TCL, which was written by John Ousterhout during his time in Berkley. i tended to do GUIs in PyGTK and let me tell you, it was a [censored] to write. i couldnt find really good man pages for PyGtk or good info at all. Thats when i changed to TCL/TK which is definitly easier, and its like java. normally you could run your program with the GUI on windows too. dont use Java. Java is evil. Java should be burned, cut into pieces and thrown away. gnome is also good, but i would stick to TCL/Tk. good thing is, you learn TCL while doing the GUIs in it. hey, another programming language learned. google has more. so much for my once per month post.
http://www.google.com/search?q=tcl%2Ftk%20perl&sourceid=opera&num=0&ie=utf-8&oe=utf-8