Here is a great article on golf apps for iPhones. Go to iphoneness.com and have a read.

I have only tried the CaddyAid app on a Nokia N95 in the past but found that it was slow to update compared to the Skycaddie SG5 my playing partner was using. Once it caught up the yardages were very similar. It was also very battery intensive and left little battery after a 4 hour round.

I am armed with the new iPhone 3GS 32MB so I will give a few a try and post my findings.