Yeah Hamachi is a piece of shit now. 4 individuals in a server unless you pony up, insistence on being tied to an account, and their reliance in Internet Explorer fucks my shit up and means I can't make it work on WinXP anymore.

There's also OpenVPN and Tunngle. OpenVPN can be quite painful to get setup in my past experiences. Tunngle on the other hand works well and doesn't have Hamachi's server limitations--however it is absolutely bloated with obnoxious ads.