Go for wxPython, it'll fulfill all your GUI needs. Handsdown the best GUI toolkit I ever ran into. It can't get much simpler than:
wx.MessageBox('hi') And there are tons of readymade dialogs and progressbars in the library. Check out the demo.py under the wxPython installation dir to see demos (and source) of the enormous list of controls. -- http://mail.python.org/mailman/listinfo/python-list