Here ya go!
http://www.smartphone.net/software_detail.asp?id=723
I've used it for 3 months. Works great! It will auto change between your EVDO data and USB data so you can separate the 2. I'm on my carrier's max plan (100MB), so I keep an eye on it always! From the homescreen!
Oh yea,,Efficasoft makes one too. Half the price, half as good. I trialed both for 30 days and the first one, by Spb, won hands down. But here is the other one:
http://www.smartphone.net/software_detail.asp?id=1353