Previously we mentioned OpenVPN, a solid VPN solution. Hamachi by Logmein.com is a VPN solution which uses UDP, non error correcting protocol wrapping an encryped TCP connection. This creates a large efficiency gain over other VPNs which wrap error correcting encrypted TCP protocol inside of error correcting TCP packets. From our testing, Hamachi was able to maximise our bandwidth of 2.8 MB/s without processor strain, while the best performance we received through OpenVPN was 600KB/s.
Unlike OpenVPN which is very difficult to set up, Hamachi sets up in about a minute and requires a virtual LAN name password. In this way your computer starts VPN connections as easily as one might join a chat room and you become connected not just to one machine, but every machine that has been authorised on that virtual LAN and whom the user has authorised. Included in the client is also an IP to IP non-recording encrypted chat mechanism.
Hamachi is freemium software and is actively developed. Here is a great podcast explaining the intelligent design of Hamachi.
Hamachi is the Japanese word for Yellow Fin Tuna.