Step 54: Camera Support: Screws to Hold Your Babies in Place
I make little DIY camera finger bolts by taking a 1/4 20 bolt with a flattened head (unfortunately, I can't find the name for this type of bolt -- let me know if you know it), and in this case, I use a nut and a washer to shorten it so that it is the right length to hold the camera securely. I have made other versions of this using a wingnut and a hex-head bolt, visible in step 51.
Update: My dad, who taught me how to use tools and build things, writes: "I think the flat head bolts are commonly called thumb screws just like their knurled cousins. ". I'll take his word for it. These are thumb screws.