This is the world that I use for building a new mini game. It is based off of a floating sand world. I removed the sand for the immediate distance away from spawn at 0,0. If you need more space, place a block on the sand and fly/teleport straight up while looking up. DO NOT DO THIS IN SMP as this usually crashes the server. You can also take the safe route and delete the layer of sand using MCEdit. I hope this comes in handy.