Sorry to bother y'all, but I've searched the internet with no results. While watching Sunday's game between New Orleans and Tampa Bay, I noticed an official in the end zone throw down a blue marker, smaller than the yellow flag, when a safety had been scored. Never saw the thing before, but since then, I've seen the blue markers, or whatever they are, hanging on the officials' belts. I've done searches and checked a football book here at home, and haven't even come close.

What IS that thing, and when is it used?

Thanks for your help.

Spot Marker
 

It is a "spot marker" and is used by officials to keep track of certain spots which might be needed when enforcing any penalties or other events during a down. Example: A team fumbles and tyhe bag is dropped at the spot of the fumble, a kick is illegally touched by kicking team and a bag is dropped at that spot, etc. Look at college officials (and HS officials in Texas) and you will see a similar bag but colored white. NFL uses blue (as do some "wannabe" HS guys).

The NFL also seems to use the blue beanbags to mark the spot of change of possession, e.g. on an interception or punt.

Hey, no reason you can't buy one of your very own...

http://www.honigs.com/store/shop.mpl?Cat=18,34&Item=259

Thanks for the answers, with a picture, even!