I have a NAT configured to run when loading up my favorite Linux distribution in VitualBox. This allows outgoing connections to work successfully.
How do I allow incoming connections to this box, like, say, Web traffic? The IP address is 10.0.2.15. A ping request from my main box results in a Timeout.
VirtualBox (after version 1.3.8, anyway) will let you map incoming connections in the NAT configuration. There's an excellent tutorial on Aviran's Place that describes the steps to configure port mapping.