Turn an ordinary clicking pen into a solder dispenser, a bit of solder comes out with every click. This takes advantage of the pen's mechanism which actually spins. You can still use the pen as a pen.
Inspired by the simpler (and in a way, better) pen dispenser in the Guide to Field Soldering instructable.
Step 1: Parts and Tools
-a clicking pen
-a tooth pick
-small length of wood, 4mm x 4mm x 1" long is sufficient
-hot glue gun
-drill with a 3/8" bit
Step 2: Preparing the Mechanism
Take the pen apart, place as much of the tooth pick into the ink cartridge, and the other end into the plastic piece that is supposed to be pushing against the ink cartridge. Hot glue the ink cartridge to the plastic piece with the tooth pick helping you make a straight joint.
Step 3: Drill Hole in Pen Tube
Using a drill and a 3/8" bit, drill a hole 1/2" to 1" away from the end (the end that is the tip of the pen, minus the metal cone). This will let the solder through.
Step 4: Load Solder
Tape the end of the solder close to the end of the ink cartridge, just below the plastic piece you glued the cartridge to. Then wind the solder around the cartridge in the counter-clockwise direction (looking with the pen tip facing you) until you are about 3/4" away from where the spring rests, then cut the solder.
(please note, I do not have any solder at the moment so I am using a reasonably similar wire to demonstrate)
Step 5: Stop the Clip From Spinning
Hot glue the length of wood on the pen tube in a way that it will stop the clip from spinning as you click.
Step 6: Assemble
Put the pen back together as you would have normally (make sure nothing is rubbing anything), but make sure the end of the solder can poke slightly through the hole you drilled. Take a bit of solder out of the hole.
You are done, and now if you click the pen, the ink cartridge should spin and it should feed about 5mm (correction, 2mm) of solder.
You can add another short pen tube with another metal tip to guide the solder.