My level 32 blood elf paladin has just taken her first tentative steps into Stranglethorn Vale, which means it's time once again to spend hours of my life running back to my corpse at Nessingwary's camp. STV is one of the toughest places for world PVP, even though the Horde usually outnumbers the Alliance there. So I try to make things a little easier for everyone by acting as non-threatening as possible to any and all Allies. Unfortunately, there's no /peace emote in the game, so I'm left trying to get my point across in various ways.
If there's an Alli questing in the same area I am, I usually /wave to both keep from surprising them and to communicate that I'm not going to attack them. I've noticed a lot of higher levels feel guilty about killing someone who just waved or nodded at them. If I run around a corner and suddenly come face to face with an Alli, I'll either run for it or start to /dance. Either on my rogue (didn't get the first move) or my paladin (not really PVP specced), I'm going to get my behind kicked, so I might as well just try to get them to go away.
It's amazing what you can communicate through simple emotes. You can even get effective quest groups going with the opposite faction, if you're so inclined. What emotes do you use to communicate with "the other side", or is it as simple as red = dead?