Below are some projects built with openFrameworks:

Clouds
[vimeo 42852185]
Clouds was a project Golan showed during a lecture last semester that demonstrated a unique take on filmmaking using a point cloud.

RealtimeOCR
[youtube=https://www.youtube.com/watch?v=S0CwYcHi26o]
This project uses openFrameworks to do real time optical character recognition. The demo is a little rough but the technology behind it is impressive. The video shows the character recognition at several angles at a decent framerate.

MadMapper Mapping Visualizer
[youtube=https://www.youtube.com/watch?v=UxyrUc9IuIE]
This video shows a demonstration of a projection mapping library in openFrameworks. The demo itself is not very impressive, and is a bit like a hello world to projection mapping, but none the less it shows you what is possible with openFrameworks.

Processing versus openFrameworks
[youtube=https://www.youtube.com/watch?v=NZG3g0NRR4I]
As a bonus this simple video shows how much more efficient openFrameworks is than processing. Two applications with the same functionality are ran in both platforms with a dramatic difference in results. Processing ran at 3 frames per second while openFrameworks ran at 45 frames per second.