I've added a mod to the server that allows you to access the DreamLand.
This is an unfinished version of the overworld that was discovered by some developers mucking about with Minecraft internals and ported to Bukkit. The Bukkit mod allows you to access the DreamLand only via beds (it must be night time); simply go to sleep in a bed, and you'll be transported to the overworld. Be patient, though; it takes some time for the overworld to be rendered, and depending on how recently it was loaded, you may warp in with the terrain unloaded. In this case, wait until your character stops falling. You may take 2-3 hearts worth of damage (I'm planning on enabling invulnerability) when you first warp into the DreamLand.
The only mobs in the DreamLand are chickens. However, they serve a purpose: If you kill chickens until you obtain a feather, you can equip the feather and right-click to fly around. Flying is a little awkward, so it may take some time to adjust.
To exit the dream world, you must fall off one of the islands. This will port you back to the bed you last slept in.
Bear in mind that this mod is exploiting unreleased code in Minecraft in order to function. There are certainly bugs.