Key distribution is hard, no doubt about that. Keybase has a pretty good idea on its head, but falls on its face at the finish line.

The keybase approach of authenticating a key belongs to someone is by signing an advertisement for keybase with your private key and posting it to a social media account. This is actually a pretty decent idea, people are generally pretty sure their facebook/twitter/etc friend is the person they think it is. The more accounts you link to keybase, the harder it is for them to spoof being you, and ergo makes your public key’s authenticity pretty good!