I had some of this hanging around from a Lord of the Rings costume (long story...no I'm not a huge geek).

All you will need is:
one hammer
two nails
string/felt string/etc...
necklaces

My necklaces were usually stored in a heap, so I found this to be a great way to keep them from getting tangled.  I hung it behind the bathroom door, so I could just turn around and pick one...much cheaper than a nice jewelry armoire.  It looks pretty, too!