[aiharkness]

I'll confirm.... I'm on T-Mobile and I tested when I first got the 9700 and had the first opportunity to test when I had 3G signal, just because I thought it was so cool......If you have 3G signal, you can do data and voice at the same time.

To repeat, being in a 3G area doesn't matter if your device drops to EDGE or GPRS.

If you have an AT&T 3G blackberry on the T-Mobile network then that would be a different matter because the two use different 3G radio frequency and your AT&T blackberry would not be connecting at 3G. But a T-Mobile 3G blackberry on the T-Mobile network and connected at 3G will do data and voice at the same time.