More to explore:
Gamer Book Holders - The Portal Bookends is Inspired by the Sci-Fi Video Game (GALLERY)
Portal Bookends (ThinkGeek)- Good gift idea for my brothers.
Portal 2 Bookends for Shelf and Books - Officially Licensed Portal Collectible by Think Geek, http://www.amazon.com/dp/B0077DOFA4/ref=cm_sw_r_pi_dp_Tu0ssb0MJ9TQV
would look awesome on your white floating shelves! Amazon.com: Portal 2 Bookends: Toys & Games