This is a modification of theRIAA's paper wallet (https://www.instructables.com/id/Paper-Wallet/). I've modified it to use a Legal (8.5"x14" I believe) sheet of paper (As opposed to letter) and is a tri-fold wallet as opposed to bi-fold. you can write on this wallet, tape it up if it gets ripped and make a new one costing next-to-nothing.
Note: The legal paper is necessary if you want to store cards in this wallet. The cards fit vertically, not horizontally as in a bi-fold. The legal paper is longer, so that there's room for vertical card storage.
Version 2.0: I've added a PDF Template of the wallet. Download the PDF, and print it out on a piece of Legal Paper. Cut along the red lines, fold on the black.
This instructable has been featured at http://dailydiy.com/

Tri-fold wallet instructable.pdf
Download

Step 1: Materials

You will need
Legal sized (8.5"x14") sheet of paper
Masking tape
Ruler
Pen
Scissors

Step 2: Initial Folding

fold the paper in half hamburger style (Line 1 if you're using the template). Then fold the two halves so they meet in the center (Lines 2 and 3 on the template). Re-fold the the first fold, with the second folds inside (see the second picture) Then fold this in thirds, again Hamburger style. (3rd/4th pictures)

Step 3: Cutting

Unfold, and use your pen to mark where I've marked on your piece of paper, than cut along these lines
(If you're using the template, cut along the red lines.

Step 4: Cutting Continued

First Pic: Fold the second and fourth flaps in from the top on both sides
Second/third: Tape the bottom portion of the two largest cuts you've made

Step 5: Refolding

Fold the paper back to how it was after step 2 was complete

Step 6: Making the Outside Pockets

This step is really hard to explain, but theRIAA did a better job then I did here, so you may want to check out that instructable for more detailed instructions
holding the wallet as I am in the picture, you will see 2 flaps and 2 holes.
Flap one goes into hole two, and flap two goes into hole one

You can tape this end if you want, or leave it open if you like having card slots on the outside of your wallet. I chose to tape it shut.