A Nickname Plugin

[geckosquid]

If the name in chat is different in game are different, asdf, it'd be hard to correlate between the speaker in the chat and the player in the game. This is talking about a gathering of more than two people, of course.

Maybe local chat could show names like this: "RP Name [Minecraft Name]"

That would be great. It would require Spout, but seeing as it wouldn't give Spout users any actual advantage, it should be fine.