well, I have a Mobile ESPN phone, and it truly is a sports fanatic's dream. You can set your phone to have updates whenever a big story breaks the plain, several choices of ringtones, and the internet is solely based on sports. It's basically having Trey Wingo right next to you to update you on sports related news.
I don't, however, use the phone for fantasy football. If I'm correct on this, this phone only does fantasy football for ESPN based leagues. I have all my leagues on Yahoo! so it doesn't really work. I do actually set my "favorite players" icons to everyone on my fantasy team, so i'll get an update whenever one of those players has some notable news to know of.