Track the newest iPhone and iPod Touch apps, updates and price changes here at AppShopper.
AppShopper Social lets you share your app interests with your friends and see what apps your friends are interested in.
Wish List: Add any app to your own personal Wish List and get notified of price changes or updates by email or by push notification. Share with your friends!
My Apps: Keep track of the apps you already own. With Push Notifications, you can get the latest updates sent directly to your device.
I use this personally, you can check out all my apps: