This has got to be the coolest hacking technique I have read.
Here is the premise:
"We (Netragard) recently completed an engagement for a client with a rather restricted scope. The scope included a single IP address bound to a firewall that offered no services what so ever. It also excluded the use of social attack vectors based on social networks, telephone, or email and disallowed any physical access to the campus and surrounding areas. With all of these limitations in place, we were tasked with penetrating into the network from the perspective of a remote threat, and succeeded."
How did they do it?? With a Macguyver'ed mouse.