why not get one of these?
http://www.google.com/products/catal...tle#ps-sellers
Once you get used to gauging distances on the course, I fear you will have a very cool $300 paper weight.
Or, you could get a laser range finder, and aim it at the flag itself. Plus you could use it for determining range at the shooting range, hunting, ... .
Matt
Edit: the GPS will give you distances to hazards though. That is a plus.