M.B.
We have one Rainbow Loom in our house, and I'll be getting a second for Christmas. My MIL introduced us to this thing back on Labor Day weekend. She has 15 grandkids, and all but the littlest ones figured it out pretty quick.
My 6 year old can put the bands on the pegs for the basic bracelet, that comes with the loom/instruction book. But, she can't, quite, unhook them and fold them over the right way without launching the band all over the house. There are also a ton of online tutorials for more advanced bracelets too.
Rainbow Loom claims it's the first one on the market, and the "original" but I read somewhere that it's the reincarnation of SillyBandz or something like that. Rainbow Loom is all plastic parts. There is one spot on the multipurpose hook that is kinda sharp. Not sharp enough to draw blood, but kinda hurts if you poke yourself when not paying attention.