1 Bic Pen = Mini Pen + Sewing Kit + Tape Holder

This one's easy and useful, especially for backpackers and travelers. In a few minutes, turn a full-size bic pen into a micro pen, mini sewing kit and tape holder.  

Supplies:

• 1 Bic pen
• 2 sewing needles
• sewing thread in the color(s) of your choice - backpackers might want heavy-duty thread
• dental floss (woven kind - works well for heavy duty sewing)
• a few small safety pins
• 1-2 erasers pulled from the ends of a wooden or mechanical pencil
• tape - electrical, medical, scotch, etc. - you choose
• optional: 6-12" of 3/4" of elastic and/or 'grosgrain' ribbon  – for gear repairs; 'grosgrain' ribbon is the ribbed kind, not the satiny kind, and is a light-weight stop-gap for strap repairs.

Tools:
Needle nose pliers are all you need if they have the wire cutter part; basically, you need something to cut and snap the pen into parts and something to pry the ends off the pen. A ruler might be helpful, but not necessary.

Bonus!
Check out my Rx Bottle Emergency Kit Instructable to see how to pack it up together along with useful items like duct tape, rubber bands, exacto blades, zip ties, a nail file (files other things, too), bandaids and ever useful paper clips.

Step 1: Make a Mini Pen

1. If you want the pen to fit into something like an Rx bottle (or Altoids tin), measure it by inserting it point first into the bottle.
2. Gently twist and pull the guts out of the pen tube.
3. Score the pen tube with a blade. Sometimes, once you've scored it all the way around, it's easier to snap it off gently with your pliers.  Sand it lightly, if needed.
4. Use the wire cutters to cut the pen. It's potentially less messy if you use a pen that has less ink in it than the length you need.
5. Fit the pen back into the tube.
6. Optional: pop the stopper out of the remaining tube, and press it into the end of your pen.

Step 2: Make a Tape Holder

This is as easy as toasting a pop tart, but...

1. Pick the tape(s) you need:  scotch, electrical, medical, stretchy, duct tape, etc.
2. Wrap the tape around the tube, being careful to roll it on straight.  Add as much as you think you might need.
3. Tuck a bit under the end so it's easy to remove.
4. Replace as needed.

That's really it...

Step 3: Make a Mini Sewing Kit

Pick your threads - for backpackers, you'll want heavy duty thread; woven dental floss can also be good (as can the threads inside paracord, but you don't need to wrap that here - just remove from paracord as needed); invisible thread can be harder to work with but it blends with everything and is a bit stretchy, so that can be nice for some repairs.

1. Begin at the bottom end of the tube and start wrapping your first thread tightly around the tube, overlapping the loose end to hold it in place.  Wrap at least 20" of each thread.
2. Add another kind or color of thread, if you want; unless you care about aesthetics, you really only need one color
3. Add the dental floss, grossgrain ribbon, elastic &/or tape. You may need to tape down the starting end
4. Insert needles, safety pins, etc. into the tube
5. Stopper the tube with an eraser (the eraser might come in useful, anyway)

I haven't yet found a great way to keep the threads from unraveling, apart from using the needle to tuck the end under other threads (which makes it harder to find the end), so I just hope for the best.  Any ideas?

Step 4: All Done!

If you want, you can now add these to your Rx Bottle repair kit, or they'll fit nicely in an Altoids tin kit.
Make as many mini pens and kits as you need... Keep a few in your bike repair kit... Give them as gifts... 

I like the Rx Bottle because it's also a duct tape holder and it's waterproof. However, it is bulkier in your pocket...