AGF Black Leather Horizontal Case - found at AT&T
I've recently picked up a Nexus 4... it must be a slightly older stock, since it doesn't have the new "nubs" on the bottom. Seeing as I'm living in a sandy, dry area (southwest US), I'm particularly paranoid about scratches from silica/sand being trapped in my pockets and from setting the phone glass-back-side-down on dusty surfaces. I promptly picked up the Spigen UltraClear Dual screen protectors (love the fit on the back - the front, not so much, but it works) and the official bumper from Google, but the bumper adds just too much girth to fit in any of 3 leather cases I have from my previous phones.
I prefer a belt-clip style pouch, and searched high and low for a compatible leather case, similar to my old favorite (Case Logic Universal - Large)... Pangilinan's earlier suggestion of the Staples Executive XL case was exactly what I was looking for, but neither my local Staples, nor their online store, have any of the XL's in stock... double
A little more searching found this gem: http://www.att.com/shop/wireless/acc...id=2hu1tiHWh_K
The fit is a little tight at first, but it relaxes into a perfect fit in about a day. It's expensive - $35 - but so far, it's the only belt clip leather case that I've found that fits well without stretching or leaving parts of the phone exposed.