CPOP (Circuit Precedence over Packet Data) is a new feature that has been added to all 1X-capable devices at Verizon Wireless according to their website FAQ.

I understand it is already running in some zones. This will allow a call notification during a data session with 1x similar to that of the EVDO notification now.

http://www.verizonwireless.com/b2c/d...IC&topicID=286

(MRAILING EDIT

I called Verizon about this, and this is the answer I received:

It went in to affect on June 21st, and for new customers it was ready and added to accounts (if you were new) on June 23rd. It will be added to all existing customers by July 15, as it can take up to 3 weeks from the June 23rd date to provision to all the accounts. So some of you might already have it, depending on when the provisioning takes place, otherwise it will happen by July 15.

END MRAILING EDIT)