I actually wanted to post the Cargo Containers by industrial designer Daniel Ballou from Long Beach, CA. But then I saw he also made these:
X-formed book ends.

It’s the X which got me. However, I’m still reluctant to really like them because books should be read in the first place. On the other hand, you always have a couple of books which sit on your bookshelves for years without being touched. So these book ends could be a good way to leave those kind of books there but give them at least a purpose. Right now, Ballou proposes no option for customized book ends, but some are exclusively available at the Open bookstore in Long Beach.

Photos from © danielballou.com