Hi this is a script heavily inspired in cinema's matrix extrude... it is far from perfect but still usable I think.
The idea is to repeat a serie of extrusions on every selected face. It works mainly with ops and can take a while in some situations. Won't update in realtime, just undo and change settings... the last extruded faces will remain selected so you can keep working on them.
Did a search and found an old script called Tesselate that should do this and more, and also Blender has it's owr extrude repeat operator -but it is kind of boring at the moment-
'interactive' version here, should work as addon also
update: wrote an experimental rigging tool to work with this script, get it here
this old one runs from properties panel and won't refresh -better for lots of extrudes-
the orginal thread in blenderheads.org