Glue gun definately but if you dont want to go to the trouble I would recommend Pritt Power Gel for a good bond. It\'s clear, dries well without shrinkage and bonds like a paw in a bear trap.
No more nails might be cheaper...not sure on that.
Anyway you can pick up a glue gun for a couple of bucks these days. I have had my cheapie outlast the one I spent a lot of money on.