I'm specifically looking for one that lets me display a map of US states with each one as it's own "object" in the sense that I can control the color, on click, and on mouseover of each one individually.  GTK is my personal preference, but at this point I'd settle for just about anything.  The application itself will be written in Python, FWIW.
Quick tip, if you color each state differently you can identify which one to pick from the color under mouse cursor rather than doing a complex point in polygon routine.
Does anyone know of a widget for a desktop toolkit(GTK, Qt, WX) for displaying a map of US states?