New behavior: Every few seconds the GPS sign appears momentarily in the notification bar, next to the Lookout icon. The only thing I've done out of the ordinary is use GolfShot today. I forced it closed in Settings. Anyway, the GPS icon keeps appearing ...
GolfShot is probably still running in the background, and still polling the GPS, most likely.
Go under Apps in your Settings, open the GolfShot app under the All tab, and see if it's still running. If it's still alive, Force Close it and that should take care of it. If you find that it wasn't still running, then perhaps GolfShot started a service that's running in the background. In that case, try to locate the service under Running Apps and kill it from there.
I think the demon app may be foursquare. When it happened again i removed foursquare and it stopped. I still had to reboot because the keyboard stopped typing letters and the time froze on tje notification bar. Ill leave it off for awhile and see if it stops.