Strava

Has anyone tried Strava? It offers:

Discover Your Ride
View your ride like nowhere else
Relive your ride with cycling-specific charts and graphs
Analyze Strava Watts, heartrate, mileage, and more

More Than A Training Log
Log all your rides easily
Learn more about your rides
Track equipment use and mileage

Compare and Compete
Get smart about your training
Compete against your friends (or rivals)

Connect... Off Your Bike
Follow your friends, teammates, and competitors
Find cycling friends in your area or around the globe
Share your rides on Facebook and Twitter

Built for Cyclists
Developed by cyclists for cyclists who say they're continually adding new functionality and offer unlimited ride storage, a clean, uncluttered interface, and dedicated member services.

They support all Garmin Edge and Forerunner devices, with support for the iPhone coming soon.

I've only signed up for the trial but I thought I'd see if anyone else has checked it out yet. I've created clubs for "Sonoma Valley Cyclists" and "CycleSonoma".