I've just found speedbar and it's a wonderfully useful tool. I really like how it can drill into (python) files to show me a list of classes, methods and functions.
Is there any way I can get speedbar to auto-expand the tree of class/function references for the file in the currently active buffer?
It would be a bonus too if I could just expand to where the current cursor is; for instance, if the cursor was located in the foo function of the bar class, speedbar would expand to myfile.py > class bar > foo.
There is no canned solution for what you are asking about. Speedbar does, of course, know how to do it, but you will need to write a new command to do it.
I'll guess you might be interested in ECB, which can serve a similar function. It breaks the side window into multiple parts, and one of the windows does follow the cursor around in the list of tags. I'll guess this is what you want.