Built-in Bookshelves

Even though I have an ereader I still find myself accumulating traditional books. Every year I go to a few book fairs and I can't help but buy a tote full when books are as cheap as $1. I end up sharing books with friends, but then I end up holding on to them. This would be fine if I had a little more space. Currently I have books everywhere, with no organization. I'm looking forward to the day that I can have room for some bookshelves. Built-in book bookshelves would be especially nice. I think through the years I will cut back a little bit, but I'd like to hold on to my favorites and my hard back Penguin classic collections.
Here are a few built-in bookshelves that caught my eye on Pinterest:

Via iVillage

Via Mark Sikes

Via iVillage