In the past I know there has been a number of discussions regarding redundancy on here, however (at the time) there seemed to be no successful demonstrations or stories of  motor redundancy with the Arducopter.  Now that a reasonable mount of time has passed, and code has progressed considerably, I thought it was time to revisit this.

Has anyone has been able to achieve at least  single motor redundancy?

An example of what I would like to see/hear about is here:

http://www.youtube.com/watch?v=6VSJYdD-Xr0