Possible Duplicate:
Is it possible in Minecraft to switch over from survival to creative in single player?
There are times when I'm in a network of caves and I get so lost that I can't get back to the entrance and I'm out of materials to build pickaxes to mine upwards and because of the load of materials I just mined dying isn't an option (because if I do make it back I'll just be lost again)
At times like this I want to switch to creative mode and fly straight up and then back to my base. I know it's kind of cheating but I can sometimes spends hours being lost, markings don't help because of just how large of a labyrinth these mines are and I already carry a hell lot of tools I don't have the space to carry anything else to make markings with without running into problems of being able to cart the stuff back home.