I just could not believe when a friend told me about it but when I used this for myself it was simply....WONDERFUL.
Just put ur username & password and sit back...
and analyse ur dataone usage...

In summary or detail, Happy Hours or Normal Hours. every thing is there.

you can even view your bill for the current usage.

I can't explain more...but just watch for urself.
download this small but stunning utility from here.

http://duf.sourceforge.net/