That's great.

Potential founders should consider the costs of providing tech support for a tunnel that crosses two NATboxes, both controlled by strangers.

If you can remotely login to the box, it wouldn't be that bad. And if you can lock down the box physically then it would be pretty tamper proof.

Anyway, it was just a thought. It's possible it's impractical :-)

A danger is that stranger will abuse your connection to send spam or even worse things. And you might have a visit from police. Also, I'm sure, reselling your home connection is forbidden by your provider. So it's kind of grey zone.

It could be restricted to a set of domains and only allow HTTP and DNS traffic.

"AirVPN"!

See illuminati vpn network.