Would anyone be interested in little tiny flags to put in your signatures? If people have signatures turned off, it won't help them to know where people are from, but it might help everyone else. For an example, look at the right hand side of the bottom of this post. You should see a tiny US flag.
I have 100 such little tiny flags, so if you want me to upload a certain one, just let me know and I'll find it and give you the image to use.