I see this more often now and was wondering what the heck it is????

From Wiki...

http://en.wikipedia.org/wiki/Library_binding

Library binding is the term used to describe the method of binding serials, and re-binding paperback or hardcover books, for use within libraries. Library binding increases the durability of books, as well as making the materials easier to use.

I had a paperback book once that had be library bound as a hardcover. Same as the other paperbacks, but a hardback.

ok thank you

Along with a hardcover binding, they are often sewn together, providing a more long lasting product. 

Sometimes the library binding is a regular hardcover....instead of a loose dust jacket, the full color picture is printed directly onto the hard cover.

Sometimes paperbacks that have been rebound as hardcovers are called Turtlebacks or Perma-Bound editions as well (not necessarily here at PBS, just in general).  According to my aunt (a school librarian) you can actually order them that way from bookstores.  I've got a couple like that, and I absolutely love them.  They're titles that were required reading when I was in school and the rebound copies are like commemorative editions to me lol

Library binding is not to be confused with library editions, btw.  While the former is the rebound version, the latter is simply a regular copy, usually with a clear plastic covering the dust jacket, that had once been the property of a library (but as since been withdrawn or discarded.)