Getting your YouTube web or client application up and running is only
half the battle. We know that you'll also want to monitor your
application to see how it's performing. Our new Developer Dashboard
shows you at a glance the number of API requests, playbacks, uploads
and errors that your app is generating. You can visualize the data
using our interactive chart or download a file to process the data
offline. To use the dashboard, you'll need to provide a developer key
in your API requests and then pass the media URLs from the API
responses to the standard embedded player or the chromeless player.

You can log into the new Developer Dashboard at http://code.google.com/apis/youtube/dashboard/