Ehci 0.5 has just been released and it now features Python bindings.
It's pretty easy to use EHCI in Python. The following snippet shows how to do it in 6 lines:
x,y,width,height = ehci.getHeadBounds()
print "Coord (",x,",",y,") width ",width,"height ",height
These two videos give some idea of EHCI integration with Panda3D:
To download it, check http://code.google.com/p/ehci