We are developing Flone: a interface that allows smartphones to fly.
Right now we are starting with the project, so first we design the airframe, it's a H quadcopter with space for electronics and free field of view for the camera of smartphone.
We would like to keep the design "mini" and easy to build.
At the moment we are using a Multiwii as flight board and a standard camera app in the smartphone.
Our plans is to develop an app than allows to fly with the onboard sensors and telemetry of the smartphone.
We plan to release the hardware with Creative Commons ShareAlike and the source code with GPL, so we would like to have the feedback of the diydrones community.
You can get updated about the project in our webpage: http://flone.cc ( In spanish )