place is the most beautiful & flexible of the Geometry managers supported by Tk. It provides support for fixed or "rubber-sheet" placement of widgets.
http://www.purl.org/tcl/home/man/tcl8.4/TkCmd/place.html
[Any examples of how to use it, or tips on things to do or not do?]
Geometry Managers Tk syntax help - Arts and crafts of Tcl-Tk programming - Category Command