Yeah, you can see the beginnings of double-stacking on the Classics shelf (third from the top on the left) - the space below it is taken up with textbooks and the space above it is traditionally for ring binders (which is why it's huge and, currently, empty), so I've had to start putting the Loebs in front of the Penguins. At least with this arrangement I can still see the start of the author on the Penguin spines, so finding things isn't too much of a nightmare yet.

When I move out, I will suddenly develop two bookshelves XD One is filled with old comics that I'm not taking with me, the other is currently empty but in an awkward place. I'm looking forward to being able to use it again...

...of course, when I move out I'll also have to take the other roomful of books with me. So maybe it's not such a saving after all. I've been clearing them out, but there are still so many left, and so many I'm keeping no matter what, goddamnit.