Wood pens that have been turned on a lathe are awesome. Unfortunately, not everyone owns a lathe (although you can make your own). The Twig Pen/Pencil is a good alternative to a turned pen, and it stills maintains an aura of originality. I got the idea for this project here. I give all credit for the idea to the author who created the aforementioned link.

Note: For this project you don't need a lathe, but you will still need some other basic tools.

Step 1: Materials

For this project you'll need the following:
A Drill w/ Small Drill Bit
An Approx. 8mm Twig
An Old Pen Cartridge or A Stick of 2mm Lead
A Saw
A Pair of Scissors
A Container of Krazy Glue
A Permanent Marker
A Vice

Step 2: Drilling the Twig

Cut off one end of your twig with a saw, and clamp the twig in a vice with the cut side side facing upward. Drill a hole down the center of the twig, until your drill bit can go no farther. Make sure to get it down the center or else you'll drill out the side of your stick.

Step 3: Fitting the Cartridge

Compare your pen cartridge/mm lead to your drill bit. You are going to need to cut your cartridge to about the length of your drill bit or maybe slightly longer. 2mm longer than your drill bit is about good. Apply glue to your now cut pen cartridge/lead, and slide it into the hole in the stick. It should look similar to the picture.
Whittle the end down to a suitable "pencil-ish" angle, and enjoy owning your very own twig pen!