I use them a lot. They are good to use on soldering projects as they don't sink the heat like metal clamps will, though I have burnt more than one in the process.

The other advantage is you can carve and reshape them as needed, especially in tight access situations.

I have them in a variety of sizes, even down to but an inch long. There must be some craft hobby that uses them, for I have found them in various miniature sizes in the craft stores.