There seems to be something about Zurich and Micro Air Vechicles, maybe it's the alpine air. This video shows the Skybotix CoaX helicopter being tele-operated through ROS. On the software side of things the CoaX, appears to be running eRos, or something similar, on-board a Gumstix processor. It has basic support for running opencv on-board and is capable of transmitting images as a ROS topic. It's not clear how the IMU and optical flow data is made available in ROS, but overall their documentation looks good.
On the hardware side, the CoaX is equipped with both a pressure altimeter, for outdoor use, and a sonar altimeter, for indoor flight. It has two dsPIC microcontrollers, IMU and a Bluetooth or Zigbee radio. Optionally it can be purchased with a Gumstix Overo, WiFi and lateral IR sensors. The 340mm rotor diameter makes it capable of flight through small apertures and it's low center of gravity makes it aerodynamically stable.
I saw their live demo at IROS 2010 and can report that the aircraft had stable flights and seemed to hold up pretty well throughout the entire convention despite the crowds and near constant demos.