For those who are interested in the Verizon iPhone, one of the most pressing questions was whether or not the phone would be able to allow simultaneous use of data and voice. This is currently not possible on Verizon's CDMA network, and is sure to be one of the big points in future AT&T advertising. Since the Verizon iPhone operates on the CDMA network, it will not be able to handle voice and data at the same time.
When you get a phone call while using data on a CDMA phone right now,
that phone call goes directly to voice mail. that phone call interrupts the data connection. Likewise, you need to hang up voice calls before trying to bring up websites or capture other data. Want to use that built-in tethering app to send a 3G signal to five devices? Just don't try to talk on the phone at the same time.
This will not happen if and when Verizon and Apple create an LTE-based iPhone. LTE can handle both data and voice at the same time, as it is based on the current iPhone's GSM technology.