Start with a PCI Slot cover (or similar) and end with a money clip that will have all the neighborhood geeks reaching into their pockets and pulling bills from far less awesome money holding devices trying to buy it from you.
And remember: your biggest bill always goes on the outside.
After reading more, post posting, I've been told that I'm supposed to provide information about why I did this. Truth be told, it was like 1 in the morning, I was bored, and I didn't want to make much noise. Not bad for a midnight project, if you ask me.
Step 1: Supplies Needed
Victim (see next step)
Nail (a pretty thick one would be best)
I'd also like to take this moment to appologize for the poor quality of the pictures. I tried, but I just couldn't get them to be sharp without the flash, and the flash likes to reflect a big white glow in the middle of the shot.
Step 2: The Victim
Here you will need a PCI slot cover of some sorts. My first clip was just that - a temp slot cover for when there's no card in the slot. The one I'll be chronicling here was a joystick extension off a soundcard or something. Thank you old hardware from Freecycle. Funny story, turns out the guy that I got the computer from writes for O'Reilly. That was pretty cool to realize, although I guess that doesn't really amount to a funny story. Oh, and save the connection - could come in handy!
I should mention that you should take into consideration how hard the metal is. The first clip I made was very pliable, and thus the crimp is a lot smaller and tighter, but the metal loses form easier and requires maintenance more often.
Step 3: Clamp and Straighten
Here I used a C-clamp to hold the little bent end to the bench and used my hand to do the initial bend before I could hammer it out. Make sure you grab the metal as close to the bend as you can. I used two hands, even though there's only one on the picture.
After that you can lay it on the bench and use a hammer to flatten it out as best you can. Don't worry if it's not perfect, a little bend actually makes it easier to get money in the clip. Also, don't forget to use a wood block so you don't scratch the metal to death.
Step 4: Rough Bend
Here you need to put the nail where you want the bend to be - I suggest around halfway, but there's plenty of tolerance there and it will still work. Then, place the nail on the edge of the bench, and clamp down. The key here is to make sure that the metal and the nail are perpendicular. Take time to ensure that, as it will pay off later. From there, bend with your hand or a hammer, depending on how soft your metal is.
Step 5: Bend With Pliars
Remove from the clamp, and continue to bend with your hands and a good pair of pliars. This is going to take some effort, and you want the tightest crimp you can manage. Here, I ended up with a sort of bowed crimp, but on the a softer metal I ended up with a tighter, smaller crimp, like that on a bobby pin. Be sure to use the nail here, or you'll end up with a useless metal V.
Step 6: DOOOONE!
1. Remove nail
2. Find a bunch of ones
3. Place largest bill you have on outside (yes, I am well aware that mine's a five)
4. Fold and place in bill clip.
5. Go to LAN, then offer to play a round for money. Whip out clip and tauntingly state: "Let's Go!"
Step 7: Maintenance
If you happen to make your clip out of a softer metal (such as the Dell slot cover shown below), every once and a while (and after large bill-count deposits) you will need to recrimp the bend with a pair of pliars, just as you did originally. I recommend once a week to every two weeks with very soft metals, and I'll let you know how often you need to with stronger metals like the one I did for this instructable.
Been a long while now, and I have yet to have to recrimp this harder metal clip.