I like this use of wallpaper, too. My tendency would be to keep the shelves white, but I think this consistent look is fantastic.
I love this little detail. It's totally unexpected and funny - and I love a funny addition to any room. We've already built a base a the the bottom of our shelves, but I'm wondering if I can add something to the base or paint it in a way that brings this kind of humor to the room.
I'm a fan of shelves that are painted in contrasting colors. In my house, if I decide not to go the wallpaper route, I'll definitely paint the back of my shelves a different color than the shelves themselves. In this case, I especially like how the backgrounds are slightly different shades. Not enough that the difference is jarring, or distracts from what's displayed, but just enough to be interesting.
This photo makes me sigh and think "if only." I love shelves that you can see clear through and these are a fantastic way to divide a room.
This is another great example of how to organize books for maximum visual impact - I love the way the colors are grouped. Plus, great narrow shelves!
This wall of shelves caught my eye because they're just so open. Many large shelving systems include lots of vertical divisions. I like how open these are, though - it adds a more modern feel to the space.