Last night, while browsing through the App Store, I stumbled across a free app, XBL Friends. The app displays all of your friends from Xbox Live on the Xbox 360 to your iPhone/iPod Touch. It's very handy when your wanting to show off your stats (i.e. Gamerscore or Achievements).
You can keep track of everyone's Gamescores, when they are playing on Live, and what they are playing. For example, we'll go into EnforcedData (my Gamertag) and see what I have done and what I have recently played.
It shows that I last played Uno (which is highly addictive), my rep over Xbox Live as a whole, and my Gamerscore. You can also see how many acheievement points I have gotten out of the maximum of each game.
And if you ever decide to delete someone, simply hit the edit button off the top and select the red button next to the Gamertag in question.
This app is available FREE at the App Store in iTunes.