This thread rocks. That is all. Oldie, but goodie:

Three men, a farmer, a terrorist, and an engineer are walking through the desert when they stumble upon a magic lamp. Upon being rubbed, a genie pops out and declares that he will present each of them with one wish.

The farmer thinks for a second, then says, "My grandpa was a farmer, my pa was a farmer, I'm a farmer. I want all the entire earth to be fertile for farming." And poof, the soil was fertile.

Next, the terrorist says, "I want a wall to be built around the Holy Land. It should be 500 feet tall, 500 feet thick, and perfectly impenetrable: nothing can get in or out." And poof, a wall appears surrounding the middle-East.

The engineer stops and thinks for a minute, then says simply: "Fill it with water."