I am now officially KU6Z (formerly AG6DI) as of Sept 16, 2011.
I wanted to get a 4 character callsign before they are even more difficult to get. Luckily I was able to use http://www.vanityhq.com/ to help me find out what callsigns were available and at what date to file. I tried 3 times to get a new calldign, and each try costs $13.30. The first try I just put in a list of available callsigns, and got dismissed because I had some callsigns that werent available on the day I filed. The second try, there were 8 other people trying for the same callsign, and someone other then me randomly won the draw. On this one, only one other person filed on the same day as me, and so I had a 50/50 chance of winning it, and I WON! Yay!