What's the coolest keyboard that you've seen? I wouldn't be surprised if you said the Optimus Maximus. Honestly, that's probably the coolest one I've ever seen too. It seems that ThinkGeek is pretty impressed with it as well, so impressed, that they have decided to add it to their site for purchase.
Don't think you're going to get any big deals over at ThinkGeek though, they're selling it for $1.589.99. At the time of writing they were also currently out of stock.
The Optimus Maximus is still one of those products that I would love to own, but could never justify purchasing. You know you have money to spare when you can actually afford a keyboard more expensive than your computer.