Being a big Australian Football League fan, (and Sydney Swans member), I was chuffed when the ultimate AFL application Aussie Rules Live was released. It has pretty much everything you need to follow your team and all the others, including live scores when the games are on.
AFL is a social game, with footy tipping giving you a reason to have a competition between your friends to see who gets through to the top of the ladder. You can extend your network outside of your immediate network to others who are also passionate about sport. It adds another dimension to use a tool such as Twitter to keep in touch with your favourite team for me its @sydneyswans, and your real and online friends live while the game is on. You can also use hashtags in Twitter Search to find conversations going on (often across the country as AFL fans have a higher representation in the southern states). So you can easily identify other AFL fans to follow on Twitter through their tweets.
Twitpic and YFrog are image posting services services accessible via web or through iPhone Twitter applications such as Tweetie, Tweet Deck and Twitterfon. My current favourite image posting for Twitter iPhone is Tumblr – another blogging platform but with a great little interface. You can even tag the photos before you upload them, or later on via the we. I love Tumblr because you end up with a photo blog, a collection of your favourite photos you can re-visit anytime. And you can sort the photos via tags too.