Storage - and lots of it!

To quote Microsoft Research's Rick Rashid: "you can store every conversation you've ever had in a terabyte. You can store every picture you've ever taken in another terabyte. And the Net Present Value of a terabyte is USD 200."

Think about it - the opportunity for conserving you family's entire history online. Every picture taken, every birthday song - etc. Facinating stuff. And with some serious business potential.