Our survival server now supports Spout mod
"On its own, it does very little. Expect no changes beyond some interface enhancements and minor speed improvements on the client and moderate speed improvements on the server.
Through it, Bukkit plugins can do the previously impossible. Currently, plugins can seamlessly manipulate and monitor inventory, audio, sound effects, skins, player titles, alter the main in-game HUD, and launch popup notifications on the player's client."