If you take a look at Pearl Jam's catalogue, they pioneered new paperstock CD packaging that has almost become the norm. It doesn't necessarily take up less room. However, there are better opportunities for cool artwork and foldout stuff. Also, it will biodegrade considerably quicker. Head to a record store (if there still is such a thing), everything after their first two discs is packaged this way.

these are damn cool, and it looks like it is not damaging to the tray art either, which is why I have kept my CDs in jewels up to this point....My only thought would be to wonder if there is wear and tear on the CDs storing them this way (from removing and replacing the CD, whenever you play them), which is what has kept me away from the CD storage books over the years, and why I don't like the cardboard packaging used with some live albums, most notably the Pearl Jam official boots.