ofxaddons yay!
1. ofxSelfOrganizingMap
This addon helps to implement a mapping of high-dimensional data to a low-dimensional space. I don’t know a whole lot of about self-organizing maps or unsupervised machine learning but I’m really interested in machine learning and from reading some of the linked wikipedia pages, the addon sounds pretty cool and may be something I’d like to experiment with when doing the data visualization project.
2. ofxOpticalFlowFarneback
I posted a video called Optical Flow Test that uses OpenFrameWorks and OpenCV in my previous post, which uses this addon. I’ll post it again for convenience:

I really hope to experiment with optical flow because I think it could be used as an awesome interface for something or as a way of exploring or mutating a virtual space to create a different kind of experience.
3. ofxGame
This addon contains useful classes for making 2d games in OpenFrameworks. The author provides a video demonstrating the addon:

Tecnópolis Pakapaka: the makingoff ofxGame from Patricio Gonzalez Vivo on Vimeo.

Making games (particuarly 2d games) is kind of my default so I imagine that as I’m learning OpenFrameworks I will want to make a game at some point. The author also suggests some Processing apps that are useful for making game objects so I think working with this addon will give me experience working between both Processing and OpenFrameworks.