ON the mine-craft forums, someone had posted that a build for 1.5_01 had came out. It is the newest craftbukkit at the moment, and is therefore unstable. (not recommended build.) There is something amazing about this new update: It automatically blocks people flying without giving them permission. It kicks them for floating too long. I find it very useful. I have no plugins that block flying. You can turn on flying because it says "flying is not enabled in this server" when it kicks you. I hope to use this. Very nice addition. As stated in the comment below I think notch added the flying. At least we have something to work with (with) the new 1.5_01 bukkit.