The cheap string tripod is a great trick when you need steady shots without proper equipment. Instructables user inspiredwood took it to the next level with a DIY contraption that makes it a much more pocketable solution.
The hack requires plywood, string, rubber band, and a bolt.
As the photo above shows, he cut out a shape in 9mm plywood and put the screw through its centre. The nylon string is already attached to the bolt in the setup, and then wound around the wood so it stays in place without causing a tangled mess. So it's only a matter of unwinding the string and screwing this wooden block to your camera when you need to take a photograph.
And that's your DIY pocket-sized tripod! This description makes it sound less complex than it is, but the step-by-step instructions at the link below should see you through the job.
Cheap Simple Tripod For Your Pocket [Instructables]