Hi everyone, 
  I'm new to OpenCV and ROS so I'm happy to mention that I'll be demoing my first OpenCV/ROS project this Wednesday at the NY HW Startup Meetup and also at Maker Faire on Sunday this weekend. Here are the two links to the events: 

http://www.meetup.com/NY-Hardware-Start-up/events/80880922/

http://makerfaire.com/pub/e/9341

All the code I wrote is in a fork off of AutonomyLab's ardrone_autonomy. I probably should have created a seperate package, I know, I'll probably move all my additions into a separate package at some point. In the meantime you can pick up my code at: 

https://github.com/FalkorSystems/ardrone_autonomy

It's not documented at all, and it has evidence of numerous attempts to try different things that failed to work very well, but now it works pretty well. I finally ended up using a Haar classifier so that I could detect a person wearing a t-shirt with my company logo, and the robot follows it. The cascade detection is augmented with optical flow in case in a subsequent frame the logo gets missed by the detector. 

Hopefully this will help other people out there trying to do similar things.