Lottery machine
A lottery machine for Minecraft 1.4, based on a randomiser design by CodeCrafted. It automatically resets itself.

Push the button in the middle and a random selection of dispensers will activate a BUD which then sends a signal to their command blocks.

To customise it you can choose which units to turn on (By doing this you choose the max. number of people that can get prizes and the min. is always zero) with levers at the rear of the device. Because the outputs go via command blocks, you can choose what prizes are handed out, how many (To each player), and to what players (Either closest, random or all - The default of this device is to random players).

The design is sort of tileable, to understand how I would recommend watching CodeCrafteds video on either PlanetMinecraft called "Easy Random number generator" or on YouTube called "Minecraft Tutorial: Easy Random Number Generator".

The download comes with 9 units which means you can give up to 9 random people prizes each time the button is pressed. It also comes in Iron and Gold variations. The default command in each command block is /give @r 264 which will give a random player 1 diamond, but whether the command block itself is activated is random and one person can receive more than one prize.

It seems that CodeCrafteds design is a bit unreliable. Hopefully it's just broken for me, but I'm working on a new design now.