Accel Golf- Tracks your handicap, keeps your score, tracks greens in regulation, putts, fairway drives. The GPS is kind of shitty but it's good to find yardage to a dogleg or creek.
Here's what I have so far. (got the iphone 3gs 2 weeks ago) myspace, twitter, facebook, DW (german news), espn score center, nytimes, shoutcast, theweatherchannel, accuweather, planets, zynga live poker, usa today, ifighter (cost), airtycoon (cost), atc 4.0 lite, fox sports, ambiance, wildwest, iball3d, Ibiza Sonica (trance), fastlane lite, ifitness (cost), zuginfo (german), colorsplash (cost). So many apps that you can get though. lol