Introduction: How to Make a Floating Island in Minecraft

First, Get minecraft, WHOA, wait you wouldn't be reading this if you didn't have it, so never mind. First, create a new save file and find a nice flat spot, higher than sea level. pic1-2  

Next, get an inventory editor and fill it with 3 stacks of sand, a pickaxe, and a shovel. After that you dig down reeeeeeeeaaaaaaly far (1*2) and climb back up one side using sand. pic3-6   

Make a small staircase that ends up above the hole as shown in pic7.  

Next climb up with sand above the hole reeeeeeaaaaaaly high and place a solid block at the top. pic8-9     

Then make a cross (about 10*10). pic10

Take out the inventory editor and give yourself enough solid bricks to make the platform and a brick of TNT. pic11

Drop the TNT atthe base of the platform. pic12-15     

Now fill in the gaps of the platform. pic16     

Your done! pic17-18

Another way to do this is instead of digging a really deep hole, dig a smaller one, put a torch in it, and climb back up. That way, It destroys the sand instead of hiding it. Idea by Raiderdk

P.S.  Sorry about this being in one step, It dosen't have a button for some reason. I'm working on another and it has them. It's weird. :(