Facebook Mentions not only helps celebrities see what fans are saying about them, it also allow the famous to tell their story, host Q&A's from their phone, and get involved in popular conversations that are trending. Using the app might be a good way for the rich and famous to stay connected to their fans.
Facebook Mentions is a free app for iOS only, and even if you are just a regular Joe, you can download the app on your phone. You won't be able to do much with it, but you can feed your delusions by pretending.
source: FacebookMentions (iOS) via RedmondPie