Using GPG more. After all the recent email leaks and privacy breaches, encryption and verification of plaintext communications is more vital than ever. If only it didn't have such a steep learning curve.
Crypto is super important, but it's way too hard to get practically anyone, even technical people, to use it. This area is ripe for disruption I think, especially as more and more high-profile leaks get released. Someone could sell some great, easyish-to-use crypto software and get a lot of money.