[Mayhem_351]

Sometimes when I unlock my phone I see a round status icon (like a checked radio button) at the top of the screen next to the power, it disappears quickly. Can't seem to find any information on the status icons. Anyone know what it is?

[RuleOfSines]

I think you're describing the Location Services icon, it means something is checking your location at that moment.

Here is what I think is the full list:
What do the icons on my phone mean? | Windows Phone How-to (United States)

[freestaterocker]

If it's a circle within a circle it's the indicator that some app or process in your phone is using the GPS unit to determine your location.

[Mayhem_351]

That's the one... strange I could find that from Bing. Cheers mate.

[Gilbert Marcoux]

:D Ha! ha! ha! "strange I couldn't find that from Bing" I never find what I want using Bing.