Well I bought a plastic bubble wrap bag (for lack of better description) from the post office today, $1.
That's what I use as my protective cover for my Glo .... it's excellent!!
I also have one for my lap top, and my tablet - been using them for ages. They bubble wrap shock protects the contents, and keeps them water proof to boot, especially when carried in the day back pack with lunch and fruit and assorted other junk!!