I picked up the EOS M recently so that I could have a camera near me whenever I wanted to take a random picture. I wanted to be able to throw the camera in the car and leave it there for extended outings without the fear of it getting damaged by other things rattling around in my back seat (like light stands, tripods, and various softboxes that tend to stay in the back seat of my car.
While perusing Walmart yesterday, I came across this - Outdoor Products Small Watertight Box. By the way, it was cheaper at Walmart (less than $7).
While the size of the box was good, it wasn't quite perfect. There was still a bit of extra room that meant the camera could bang around inside the box. Therefore, I went to Hobby Lobby (just down the street from my house) and purchased a sheet of 5mm thick craft foam ($1.29). I cut out the foam to fit the sides of the box and glued the pieces into place. The foam does three things:
1) Makes the camera fit more snugly in the box
2) Protects the camera if the box gets jostled
3) Disguises the contents of the box to prevent it from looking like an alluring object for would-be thieves
I'm really happy with the way it came out. Now I have a tough, rugged, waterproof box for storing my EOS M. Total cost was around $10.00.