I did some experimenting this weekend with rebar. With a little help from Tony Bubb, I figured out how to make rebar staples, how to put them in to the ground, how to use them and how to take them out again. The reason you might want to do this is because it makes any installation that would have exposed rebar much safer. The staples are hammered all the way into the ground so people can't gash their legs or impale themselves on your rebar.
I made these staples out of 1/2" rebar (40 grade -- the stuff you find at Home Depot). You can't use 3/8" -- it just doesn't work. I used two 5' lengths of 1/2" galvanized pipe. You put about 2" of the rebar into one pipe and the rest of the rebar into the other pipe. Then you hold down one and lift the other, attempting to bring them both together. You might want a second person to hold down the pipe but I just used my foot. As you can see from the picture at the left, I was able to make 4 pieces with nice bends in them. You can also see the 3 pieces of galvanized pipe (one very bent up).
In this process the lip of the pipe can get (probably will get) bent up. To some degree this means you are using up this pipe but you can rotate the pipe to get an unbent lip or swap ends or, ultimately, cut the end off. I'm not sure it actually makes a difference, but, then, I've only done 4 pieces. If I did all 20 that I need I might discover that the end of the pipe becomes worthless.
Just like regular rebar you need to hammer it into the ground. The hard part comes if the rebar is too small or if the bend isn't tight enough -- too much energy will go into bending the staple farther. Also, if you hit it too much on the bent part it doesn't seem to go in as well. Try to hit just a bit to the other side and it seems to work fine.
If you are going to attach something to it (say, a guy line) you might want to stop just before the bent part touches the ground. You almost certainly want to stop before it's all the way into the ground so you can tie something to it. Be careful you don't bang on the line when you hammer it in the rest of the way. You want to pound the rebar all the way into the ground because that way no one can kick it or trip over it or any other bad things.
The traditional way to get rebar out of the ground is by twisting it with vice grips. That's not going to work here because the bent part is in the ground and prevents it. You need something fairly long to get under the staple part and lift up. I used the 5' piece of 1/2" pipe and it worked but I bent the pipe all to hell (notice pipe on the far right). So I went out and got the biggest crowbar that OSH sold (there it is on the far left). I recommend that you use a breaker bar or other piece of solid metal instead -- it's probably cheaper and easier to get under the staple.
I took a piece of heavy rope, tied the ends together with a square knot and use that to grip the staple. I pushed a loop under the rebar staple and then slid the big bar through the two loops. Now I just pulled up, looking out for the rope slipping. The rope will slip down the bar when the angle gets high enough -- just slide the bar through the loops and lift again. Be carefull -- you can apply a LOT of force here and you want to make sure you know where that force will end up.
The rebar staples take time to make and they aren't good for all uses (if you're going to attache a leg of a structure to a piece of rebar you need straight rebar). They are harder to remove. And they only represent a marginal improvement in safety -- you can cover regular rebar and if you put a guy on it people can still hurt themselves with the guy.
On the whole, however, I would rather use staples and if I have time, I will.