Try restarting your iPhone by holding down the sleep/wake buton and the home button for five seconds. Make sure your firmware is up to date (2.0.2). If this doesn't fix it, either wait for the 2.1 update (coming in September) or take it to the genius bar. It has a one year warranty, so unless its abnormally slow, I'd just deal with it until the update. Lots of people have had this problem. Try searching the forums for more ways to fix it.