We have a number of build configurations that we like to run whenever the build agent is free (e.g. running tests using the UI/Application Monkey exerciser on our android app - http://developer.android.com/intl/de/guide/developing/tools/monkey.html). At the moment we just set these as continuous but to get a CI build to run you have to manually stop the UI exerciser tests build.
I have looked around in the docs to see if there is something that would allow us to execute this sort of behaviour and can't seem to find anything. So would other people find this useful? A build trigger that is run when the build agent is idle, and is automatically stopped when I higher priority build comes along.