Originally Posted by Diggs
The Radio Shack magnetic wire will work, but it's a PITA to work with IMO. I used it on a couple of projects, but will look for alternatives.
I've used that same wire and agree it's a pain to work with. I since have switched to using the small wire from inside old printer cables. Not the new USB cables, but the old serial cables that have about 20 wires in them. They have something like 20 different wires in them, each with a different color insulation. These individual wires are very lightweight and thin, but not too brittle (I used to use the wire from old telephone extension cables but that was too brittle). Very easy to solder up; you just use your soldering iron tip to melt a little of the insulation off to expose the wire to solder on to.
Go to your local thrift store and you can buy a six-foot or longer cable for a buck.