The iphone could be my ticket to insanely amazing fitness. Here's how:
1) iTunes. Even if I forget my iPod, my phone has my entire playlist. No excuse not to work out.
2) iTunes movies and TV shows. Today I felt lazy. But I knew I needed to work out, so I hopped on the elliptical and watched an entire episode of Millionaire Matchmaker on my phone! And I got a decent ab workout from laughing really hard while listening to Patty Stanger admonish her millionaires.
3) Apps. Seriously. There's an app for everything. Weigh yourself with an app. Track your nutrition with the LiveStrong app. Check into a volleyball gym via foursquare. Upload your workout pics via twitpic. Annoy your friends via your facebook app by tracking your workout progress. You can do it all ... or nothing at all.
The one drawback to the iPhone, however, is that it's not very waterproof. Best to keep the sweat to a minimum.