For anyone with A LOT of time on their hands, here's the papercraft version of the Yoshimoto cube:
http://www.korthalsaltes.com/pdf/six_pyramids_in_one_cube.pdf
Free prop...with directions: http://www.youtube.com/watch?v=hbJHoETWW78&feature=player_embedded
-Nick
http://www.korthalsaltes.com/pdf/six_pyramids_in_one_cube.pdf
Free prop...with directions: http://www.youtube.com/watch?v=hbJHoETWW78&feature=player_embedded
-Nick