I have to say that I have seen mix3d3m0ti0n5's homemade nursing necklace and it's gorgeous!
And when my ds saw it, he wanted it for his own! :LOL
So as you can tell, we definitely recommend them.
The one that I bought from a company is more "kiddy" oriented. It has cats and fish on it, and it's cute, and my ds loves it.
But I'm really looking forward to having one like mix3d3m0ti0n5 mentioned that looks like a pretty "grown-up" necklace that momma will love to wear everywhere, and that will be safe for baby to play with, too.
Oh I also wanted to add that the "better" nursing necklaces will have a break-away clasp so that if your dc pulls or yanks on the necklace, the clasp will just simply open, and momma won't have any pain from the necklace being yanked hard around her neck. The break away clasp also helps prevent strangulation.
However, even though these necklaces are "safe," I never let my ds play with it unless I'm with him and watching him.