I would look for ViewTi (Golf, N) versions for good GPS based accuracy with yardages and a great database of courses. It was $25 for ViewTi N (green view only), with score cards for up to four players, and stat tracking. $50 for the full app (ViewTi Golf) included fairway view and zoom in/out over the course to see the full view of each hole. You can also try Golftraxx for basic yardages from each tee, distance to front/center/back of hole, and score cards. I think it was $5.
I love my 3G iphone, and now it's my golf GPS device too. My buddy spent $350 on a Sonocaddy, where I only spent $50 for the ViewTi Golf app on a phone I already owned. :)
Best,
Brian