Me and a few buddies play Command and Conquer Generals. It's a decent RTS, but has problematic networking issues. Before giving up, I came across Hamachi which is an awesome VPN app.
It's free for small networks, and it is brain-dead easy to setup. Once all of us had it installed, we connected to the same network and were able to play as if we were in a LAN party. I was expecting some type of network latency going through the software, but I was pleasantly surprised at the results. I couldn't tell a difference.
Soon I'll probably install it on our office Media / File Server so we can transfer files and screen share remotely using bonjour without touching our router.