I use plastic cat litter boxes for many of my snakes. They come in a variety of sizes and they are inexpensive at places like Wal-mart. They are easy to clean and cheap. I use the dark colored ones for more security for my snakes.
I simply cut/melt an entrance whole with a soldering iron on one end and voila! - instant hidebox.
They also make good large water bowls for snakes that like to soak occasionally.