Cell Phone party lines

Do any present cell phones have the abilty for several user to talk to each other on the same line at the same time?I believe that walkie talkies work like this.

Say Bob calls carol and begins talking, and then Joe calls carol too, and taps into the line automatically, allowing them all to talk to each other at the same time.

Yes, more or less. Every cell I’ve had has supported conference calling, which is what you are describing. While in-call, if I receive an incoming call (or make a new call), I can answer it and then select “Join” or “Conference” off the call menu. It’s not automatic, but it lets me speak with both (and each with the other) all at the same time. Each of the other participants can then call another party and conference with that party, and so on. If I decide later that I only want to talk to one of them, I hit “Unjoin” and can then speak with one or the other alternately, or disconnect one of them. My current phone even supports a transfer – I’m talking to Bob, then Carol calls, so I answer, chat for a minute, say “Here’s Bob, I gotta go,” and hit transfer, which connects them to each other and disconnects me.

It’s not a walkie-talkie, and it’s not a party line – cell phones don’t have “lines”, per se, so the phrase isn’t quite accurate – but it does allow multi-party communication.