The casabella pouch is a micro-fiber, draw-string pouch. The material is thicker and more furry than a standard fine micro-fiber sunglasses pouch.
It fits the Nexus 4 perfectly, with enough room up top to allow the draw string to close the pouch, fully protecting the phone. There is also enough room inside that you are not dragging all sides of the phone against the material as you remove it from the pouch. Some people might say they like a tight fit because it cleans the phone when being removed, but I think it just adds to the likely hood of scratching the screen.
I also tried this Green Onion case when I had the Galaxy Nexus: http://www.amazon.com/Green-Onions-S...en+onion+pouch
It's a really nice looking and feeling pouch, smaller than the Casabella, and also a thinner less furry micro-fiber material, but still not as thin and some of the $2 ones on amazon. If I'm remembering correctly, this pouch will not fully zinch on top, but it's pretty close. There will also be more rubbing going on pulling this out of the pouch. Remember I used this with a Galaxy Nexus and don't have it anymore. It will be a tight fit on the Nexus 4 but should work.
The Green Onion pouch also as a small pocket on the front for a credit card or ID. The white version gets dirty quickly but a grey version is also available.
Gizmoskin Ultra Slim Slip Pouch: http://www.amazon.com/Ultra-Pocket-P...alaxy+s3+pouch
Nexus One style Android Neoprene Pouch: http://www.ebay.com/itm/Android-Neop...item416e20f4ee
Tech 21 d3o Leather Pull Tab Pouch: http://www.amazon.com/21-Leather-Sle...+21+slip+pouch
I had the smaller version of this pouch for the Nexus S and it is very high quality and worked as it should. It was a fairly tight fit on the Nexus S. Also, looking closely at the picture, the design has changed slightly from the Nexus S version - there is no credit card/ID pocket on the front anymore. I expect the quality to be the same, but can't say for sure. d3o is some alleged impact resistant technology/material.
Spigenn SGP Leather Pull Tab Pouch:
Galaxy Nexus Version: http://www.amazon.com/Spigen-SGP0865...d_sxp_redirect
SGS3 Version: http://www.amazon.com/SPIGEN-SGP-Ver...alaxy+s3+pouch
Krusell Luma Premium Leather Pouch for 4.3 - 4.8" Phones: http://www.amazon.com/Krusell-Premiu...ef=pd_cp_cps_2
Krusell in various colors: http://www.mobilecityonline.com/wire...roductid=30672
Mofi Kangaroo Pouch for SGS3: (UK) http://www.amazon.co.uk/Luxury-Black...627706-3412713
igadgitz Synthetic Leather Pouch:
Galaxy Nexus version: http://www.amazon.com/igadgitz-Synth...ef=pd_cp_cps_1
SGS3 Version: http://www.amazon.com/igadgitz-Smart...itz+pouch+sgs3
Phone dimension reference to help with accessory selection:
Nexus 4: 5.27 x 2.70 x 0.36 (133.9 x 68.7 x 9.1 mm)
Galaxy Nexus: 5.33 x 2.67 x 0.35 (135.5 x 67.94 x 8.94 mm)
Samsung Galaxy S3: 5.38 x 2.78 x 0.34 (136.6 x 70.6 x 8.6 mm)
Samsung Galaxy S2: 4.93 x 2.60 x 0.33 (125.3 x 66.1 x 8.49 mm)
HTC One X: 5.29 x 2.75 x 0.35 (134.4 x 69.9 x 8.9 mm)
It looks like most pouch style accessories for the Galaxy Nexus,Galaxy S3, and HTC One X will fit the Nexus 4.