ImageHamachi is a VPN application that will allow you to set up VPN connections thru firewalls easily. HamachiX is the Mac OS X front-end for it.

I’ve used this connection on the road to be sure that my data was transferring securely. This will also allow you to connect to network drives or printers that may be on your home or office network.

HamachiX is free and can be downloaded from the HamachiX website.