I love them. There was a time when I always had one on a large cardboard that I could push under the sofa when I needed the table. Believe me they helped my sanity during my last few years as a dub.
I had to give them up when I got cats because they thought all those nice little puzzle pieces were cat-sized hockey pucks. Chewed up pieces just makes the puzzle very unappealing.
Well. I've been found a puzzle website that is awesome. Free online puzzles at http://www.jigzone.com
You can change the size and nuumber of pieces and the cut patterns. Plus there are dozens of images to choose from.
You don't have to register to play.
Be careful. They are addictive.