Have you been looking for a way to allow admins to go undercover and catch those doing wrong when they think no one else is watching? Well, SneakyAdmin solves that.

How it works:

In the config.yml, you insert the names of admins that want access to this ability. Anyone not on the list will not have the ability. When a player on that list logs on, he or she will have a random name and be the rank you set in startgroup. When they decide to switch to the higher rank, they type /adminme and get promoted to what group you designated in the config.yml. It willl broadcast a neat little message like "xravenz thinks that Notch smells!" to inform players an admin has just came back. When a player on the list leaves the game, he or she will be demoted back to the start group.

Configuration:

command: the initial command to promote (on GroupManager this would be manuadd)
startgroup: the group that the admin will log into
group: the group that /adminme will promote the player to
admins: list of admins who are given this ability (NOTE: Anyone on this list can promote themselves, be careful!)
WARNING: Make sure there are no extra spaces before or after any lines in the config.yml, will cause errors!

Side Notes:

It's entirely up to you to disable OP color for those who are OPs. I have yet to implement a way to hide this player from the "xravenz has joined the game", so disabling those might be useful.