Push to talk, or PTT, is a walkie-talkie-style service offered by a few cell phone carriers as an alternate method of communication. Instead of dialing your friends' phone number, you just select their contact name, hit the PTT button, wait for them to answer, and start chatting. You can also have conversations with multiple people simultaneously. Another great advantage of the PTT service is that it doesn't use up airtime minutes, possibly saving you quite a bit in cell phone charges.

The only U.S. carriers to offer push-to-talk services are currently Sprint-Nextel, Verizon, and Cingular. Unfortunately, you can't transmit PTT messages between different networks, so, no, if you are a Cingular customer, you won't be able to send PTT messages to your friends on Sprint. Either you have to transfer over to their carrier or vice versa. Also please note that not all cell phones support the push-to-talk service, and both of you must have a cell phone that has PTT support. For Cingular, there's the LG F7200 and the Samsung SGH-D407, while Sprint offers the Sanyo SCP-2400 and the Sanyo RL4930 among many others.