Road warriors are familiar with this situation: you take your laptop out for a walk, set up in a WiFi-enabled café to try to do some work (or perhaps do a client presentation), but you seem to have forgotten your work files in your office PC. And it’s a weekend and no one can email the files to you!

Hamachi can solve your problems. It’s a free virtual private networking (VPN) tool that lets you connect to your home or office PC as if you’re in your own Local Area Network. In fact, Hamachi can connect you with anyone else who has the software running on their computers—your friends or colleagues—as if you’re in the same network. And the great thing about it: it’s secure.

How does it work? Hamachi works by bootstrapping an ad-hoc UDP connection between two computers (or among three or more in a larger network). Normally, your computer will be unable to see computers outside your own LAN or ISP due to the basic design of networks. So in order to hook up with a remote computer, Hamachi actually serves as the notification server that tells each client computer the exact IP addresses of the other computers so a “local area” connection can be opened up between each PC through a UDP connection.

What can it do? With Hamachi, you can exchange files between two PCs in different networks (you can be at opposite sides of the globe) as if you were dragging and dropping files from a shared folder in your LAN. You can browse the other computers’ shared folders, and even control those computers via Remote Desktop or VNC. You can also chat with people on the other computers.

For WiFi junkies and road warriors whose office is anywhere with a WiFi connection, Hamachi is sure to be a useful tool!