I, (and my friends) use a craftbukkit server, which is about 130 meters high (displayed with F3) and we want to know whether its possible to create an higher world. (And how to create it) Hope my english is bad enough ;D
There is a way (and for singleplayer a plugin has been made - yMod), but it means hackin into the server itself, whereas bukkit just envelopes the server and listens.
ok thats all i want to know 1 of my friends read that in survivalmode the height is less than in the other mode but i dont know which mode we´re playing ^^
You can't with CraftBukkit. Its pretty damn old now though, and not updated. You'll be missing out on a lot just to get the extra world height.