What's using my GPS? On my Android phone (a Desire HD), the GPS indicator is currently on &amp; flashing away.

How can I find out which app is responsible for using the GPS?  I have my suspicions but would like to know for sure.

It's rooted &amp; I'm more than comfortable interrogating /dev or somesuch.  Running 2.2.
Install Spare Parts.  Open it and click on "Battery History". Select the drop down list at the top and from it choose "GPS Usage". It will show you what apps have been using the GPS.

Note that you'll need to have your device unplugged at the time as it's actually looking for battery usage as used by apps accessing GPS.