I got an email from Bryan Thornbury, a student android developer who asked me to pass on some information about his free Android GPS golf app. It works with Google Maps and your phone’s GPS to calculate distances. He says that it offers good accuracy:
This app is an extremely easy to use (and free) range finder available on any Android Smart Phone. The accuracy is comparable with very expensive range finders. I personally compared it to my friend’s $500 laser range finder on the golf course. Measuring to the flag, the app showed the same distance as the range finder.
I have no way of testing it (I’ve got an old BlackBerry), but if you have an Android phone, for the price, it is worth a try.