Back a few decades ago, you signed expensive (or inexpensive) contracts with pens. If you've watched Mad Men, I've always thought expensive contracts involved lots of paper work, a few signatures and celebratory glasses of your given poison.

But, there are now people signing near-$100 million contracts with their fingers, on an iPad. NBA team Brooklyn Nets' latest player, Deron Williams signed his new five-year, $98 million contract on an iPad using the SignNow app. Yes, $98 million, using his finger, on an iPad.

Williams' took to Twitter to capture the moment:

Where to from here? We're signing super-important, multi-million contracts on iPads, where can we go from here? I'm guessing retina-scanning cameras, Google's Project Glass, and more. Technology is really advancing us, and there's no limit, the current limit is just our imaginations, and even then, there's no stopping us.