Air car usage tracking

Is there a utility out there that would allow me to track the # of GBs I am downloading in a period. Like most, my air card limits me to 5 GBs per month, and I don't want to go over that if possible because of the cost involved.
I thought I've seen free utilities that will do that in the background but don't know where I saw it.
If someone can help I'll be very appreciative as always.
I use Win XP pro.
Floyd

 

Perhaps this will help
http://www.thinkbroadband.com/tbbmeter.html

Alan

 

Some companies will e-mail you when you approach the 5 gb limit or turn off the service. You can check with your air card company.

 

Alan 12345, Thanks for the tip. It's just what the Dr. ordered and more.
Thanks again.
Floyd