So I ordered this stuff and received it yesterday.
I made a custom orthodic insert (I'm 3/4" taller on one leg than the other) that fits both my foot and my shoe, and costs $580 less than my orthodist charges for a custom insert (which sucks). This took 150 grams, so two 100 gram packs, and cost $30.
This one feels perfect, because I made it with my foot and my shoe, rather than from measurements. I put the stuff into a plastic ziplock sandwich bag so it wouldn't adhere to my shoe or sock while I was forming it, and then took it out of the sandwich bag before it hardened.
I used the leftover from a 100 gram pack to put a handle on a crappy old can-opener that's always around because it's the only one that just keeps working with all the more complicated stuff breaks.
To make new chair sliders, I put a pea-sized amount on the bottom of some chair sliders that were crappy and broken. I put a small piece of aluminum foil over them and then sat the chairs on the floor (this is after learning that sugru preferentially sticks to floors rather than chair sliders) to flatten them. Worked great.
Also used it to fix a broken bracket on the dishwasher foot kick plate, so now that stays on correctly, and put a small grip on my daughter's crochet needle so it won't hurt her finger to use it.
It starts out exactly like play-dough as they indicate. You can press it, roll it, flatten it, wrap it, and mash it as you please. It's very tacky, and a small amount will stick to your fingers, under fingernails, etc. It mostly washes off in the sink, completely washes off with a washcloth or after a shower. It takes 24 hours to completely set, but it's mostly done in 18. For about six hours, you can continue to refine it and work it as it hardens. You can easily shape it with simple tools like a butter knife if you want a more refined look, and after about two hours it will no longer stick to tools you shape it with.
This hardens to a much harder plastic than I thought it would be. It's not rubbery at all when its set, it's basically a hard plastic set.
I've already got a use I'm going to put it to on the boat: As a fixture for holding the vent tube in place on my vent-tube-led-aft mod. Basically all I'm going to do is take a 3/4" vinyl tube, stick it into the vent hole, build up a few grams of this around the tube and hole, put a loop in the tube as a water catch, and then lead it aft through the bilge and out the steering hole boot so that I can plug the vent hole right next to the ballast gate instead of sending someone down into the cabin to root around when we come in and go out. This one is simple: If it doesn't work, no harm done and I can just cut it off.
I'll post how it goes.
wonder if they will come out with a product that replaces the vise grips 
