You guys think you're being cute, but I can drill square holes!
Amazon.com: DELTA 14-651 Professional 1/2HP Bench Mortising Machine: Home Improvement
I can mortise really nice rectangular holes too.
Not sure if you're familiar with the tool, but it has a square chisel that surrounds the drill bit. The chisel cuts through like butter, because there's virtually just the corners left for mortising, after the drill bit hollows out the center.