We have created a demo about visualizing a simulation on Google Earth. The demo will be part of OMNeT++ 4.2, and for now there is a separate download so you can try it before 4.2 arrives. We have also recorded a video about it. The demo simulates a wireless mobile ad-hoc network, where cars move about randomly over a 2km-by-2km area. They have identical radios, with a transmission range of about 500m; for simplicity, we assume that the area covered by each radio is a perfect circle. When two modes move within range of each other, they can communicate with each other, forming a (usually disconnected) ad-hoc network. The purpose of the simulation study could be to measure how long it takes to disseminate some piece of information to all nodes of the network. The communication itself is not modeled in this demo. Visualization shows the mobile nodes themselves (a 3D car model), their recent trails, their transmission ranges, and the current connectivity of the network.