Cheap foam filler is normally used to fill gaps in homes for weather-proofing and insulation. You can also, as this DIY project shows, use it to create a moulded case for your stuff.
Rob on MachinistBlog.com filled an old drawer with the foam to create a cushy container that molds perfectly around his tools. Check out the link below for the full instructions.
You could also modify this project to create a protective container for your photography equipment or other precious cargo in other containers.