Plexiglas is a very cool material, a clear, tough plastic that can be used for a variety of projects from see through cases, to a pseudo blast shield, to the tripod I will teach you how to make. While it's not technically a tripod it serves some similar purposes. By itself it can hold the gopro on top to gain a little more height. The gopro can also be hung underneath if you are trying to show how to repair something on a car and the plexiglas will protect the camera from harmful slag while welding or grinding. Also with the new wifi live view function through wifi on the Hero3 cameras the "tripod" can actually be used as a cover over the gopro that holds your ipod or phone on top.
Step 1: Cut a strip of Plexiglas the proper way (Scoring)
For this step you will need the scoring tool (Or box cutter or x-acto knife), the ruler and the quick grips.
You will begin by scoring the plexiglas. This part is crucial as where you score is where it will be "cut". If your line is crooked your "cut" will be crooked. You must also take special care to cut clear to both edges, if you don't cut the edges it will shatter on the ends and destroy all of your work. The way I have found that works the best for this is to clamp down the ruler where you want to score and make sure to get the metal banding on the ruler on the side that you will be cutting. Once you have your guide attached you will begin scoring. Push your scoring tool up against the metal edge and pull toward you, little spirals of the material should come out as you go. You will score the piece several times. From what I've found, the longer the line you're cutting the more times you'll have to score. You will need to score roughly 10 times with the tool. Also the scoring tool is fastest, you will need to make roughly 3 times as many passes with a box cutter or x-acto knife so I'd recommend picking up one of these scoring tools. They're only about 5 bucks at Menards and they work really really well.