Bukkit

Suits

You just enter the command: /gethead and then the player name  and then the head appears in your inventory.

Server Spook

ExplosiveArrows

BlockSpoof - Invisible pressure plates, secret entrances and more!

Bukkit plugin for counting cookies eaten

NickMe lets you nickname yourself!

A Plugin that creates a custom spawner near a player, assigned or randomly.

A plugin to bring 4chan/Yotsuba-style greentext to your Bukkit SMP server.

A stick for hide and seek

This plugin allows for furnaces to be enchanted!

TagMe

Small additions to your SMP. Such as invis item frames and custom events.

Calendar

BacketBowAPI

In this Plugin you will walk on Ice (or the other Material in the Config).

Plugin that allows players to be jailed for placing illegal blocks by a police rank

Let your players buy the sun!

FireFix

FunCmds is a fun and easy to use plugin that allows the player to execute 'fun' commands.