If you have internet on that phone, those charges would be for every time the internet is accessed. Just remember, many apps access the internet.
Also, if you have texting on that phone the wap.cingular shows a charge whenever a photo is sent or received.
It could also mean you are being charged whenever your e-mail is accessed if you have that service on your phone.
The best thing to do is to either go to your service provider and have them look up the charges or call them, but calling will sometimes get you a very stupid customer service person.
I hope this all turns out to be nothing.
Hugs.
JoAnn