What sites support Garmin Edge 200 .FIT format?
@freiheit answered above, but I highly recommend strava.com as the added component of segments and battling it out with my friends over a section of road whether or not we are riding at the same time, or even if we are, seeing how much time I took back (or gave up) on a hill is pretty cool. 

With a paid membership they add additional ride analysis, such as HR and power. With your entered body weight and bicycle weight it will estimate your power and have found it to be a little off of my measured power, but it is always off by the same, so you can use it for trends (up or down) but wouldn't compare it to other cyclists too much.

I prefer it so much that I am now logging all my rides, runs, swims and other workouts, basically using it as my training log.

Another option (not a website though) is SportTracks from Zone Five Software, download this onto your computer and import your rides, your data on your computer. I've used their free version and have to manually upload/import my .FIT files. I think the newer version will read right off your device.