[off-topic] dynamic generation of XY graphs

Any recommendations for creating an overlay of a changing 2D graph? I have a few hundred points of x/y data that changes as the user moves the cursor around. I want to show this as an Ogre overlay.

I'm looking for a python graphing package that can yield a raw image buffer suitable for doing a dynamic update of an Ogre texture. I don't want to write to disk and then read it back in. Thoughts?

You could check out Matplotlib for some ideas:
http://matplotlib.sourceforge.net/

You can obtain the raw image buffer from a canvas, and after invoking a canvas redraw, update an Ogre texture accordingly. Note I found the redraw a bit slow so it may not fit your needs.