One thing dropbox and other cloud-based sync providers have going for them is that they've solved peer-to-peer NAT fairly well. I've always thought that the si

One thing dropbox and other cloud-based sync providers have going for them is that they've solved peer-to-peer NAT fairly well. I've always thought that the simplest way of solving the problem of "I want to sync an arbitrary amount of content between two computers, and I don't care that it's not available 'in the cloud' when all my machines are off" is to build a communication channel on top of dropbox (or something else). Although it's likely that Bad Things could start happening once your usage profile starts getting attention.