I don't like having my phone in the bottom of my pocket. The QuickDraw effect is also a plus! In this instructable I'll teach ya how to mod a metal phone case with a clip from a normal household item - a tape measure.

Step 1: Case

This will work on both plastic or metal cases. I prefer the brushed stainless.

Step 2: Tape Measure Clip

Grab a Phillips and detach the clip from your handy measuring device.

Step 3: The Clip

Some of the clips protrude out the back a little so you may have to file it flat.

Step 4: Mark It

Lay the clip on the phone wherever you want to mount it and mark it with a marker. I wanted my phone to hang upside down in my pocket so I marked the bottom of the case.

Step 5: Drill It

I used a drill-bit the same size as the rivet.

Step 6: Sand It

Since the case is brushed stainless I was able to follow the grain with a sand sponge to smooth out any burrs from drilling.

Step 7: Double Check

Yup, this looks like where I want it to be and it lines up perfectly

Step 8: Place Rivet

Now just push the rivet through from the inside. (This way there will be a very minimal smooth area against the phone).

Step 9: Add Clip and Washer

Slide the clip over the end of the rivet and go to town! (The hole in my clip is a little larger than the rivet so I found a washer the same size)

Step 10: Pop the Rivet

You can use a handheld rivet gun or a fancy hydraulic one that takes less time. They usually pop it tighter and more secure. (Not pictured here but I grabbed a small nut driver and held it against the washer just to make sure it was seated well).

Step 11: File Down the Rivet (optional)

I used an aluminum rivet which is a little softer to file. Grab a small file and slide it in the spacing of the clip.
This is optional as sometimes the back of the rivet helps it stay in your pocket a little better.

Step 12: Material Over the Rivet

Place a small piece of felt or loop-Velcro over the rivet so that it doesn't scratch your phone.

Step 13: Done!

This literally took about 5mn to do. It cost me nothing but the price of the case. I already had a tape measure laying around and the rivets as well.
Your end result is a low profile, very durable, metal clip mounted to your iphone that doesn't change the structure of the phone itself. It doesn't void the warranty, and it is very simple to do.