You might want to look at this product:
http://www.amazon.com/Cascade-Designs-50...ck+staff+travelIt collapses/disassembles into a fairly small package.
It is a bit more heavy duty than most collapsible staffs. One end has a very durable carbide spike concealed by the screw-off cap and top has a sturdy walnut knob.
I've used one of these for years and, while it certainly wouldn't be my first choice as a defensive tool, I would pick it over any other collapsible staff I've seen.