With Windows Phone 7 apps I often used ScheduledActionService.LaunchForTest to make background agents run quickly when debugging so I didn't need to wait 15 minutes before they would fire.
With WinRT you can now trigger the Background Task directly from Visual Studio. To do so:
- Bring up the Debug Location toolbar. Right click somewhere in an empty toolbar if you can't find it.
- Trigger the code that registers the background task.
- Click the dropdown next to suspend and select the class that the background task runs.