Channel walkie talkie script?

I'm looking for a simple script that lets people talk to each other (and listen) on a channel other than channel zero. I've seen these in a million different items, such as helmet cams for Star Wars armor suits, but I can't seem to find the script itself. Can someone point me in the right direction? In function the script basically lets people type, say, /7 [chat here] to talk to each other on that channel.

There's one coded by Sneaky Magic that he made available at http://www.z3row3b.com/slscripts/lsl/Sim_Wide_Chat.txt. (Despite the suspicious looking website name, I can assure you that the link goes to a perfectly ordinary text file.)

Thanks! A friend scripted one up for me quick after seeing this; I'll compare the two and see if one has any advantages over the other.