http://www.virginmobileusa.com/mobil....html?tab=tab2
either the mifi 2200 or the peeL 3200 will work. the peel 3200 says it's for ipods but that's only for the sleeve functionality it's just a a highly miniaturized wifi to cdma (3g wireless bridge) that's my solution due to the low cost.
500 mb would be unacceptable if i needed to support streaming but my applications on the go are non-multimedia browsing and voip.
I suspect the mifi 2200 would be more suitable for you due larger more economical in those quantities, data blocks. Also the Peel 3200 only supports WEP, which would be a deal breaker for me but the signal is only good for 20 feet (I read the manual). Both are pretty economical solutions unless you need tons of multimedia for your applications.
Luck, mark