Thanks for your responses!
inobobo - I think I would be too worried about the effects of the cable bending at such sharp angles. My M50 cable stopped transmitting both channels after months of use. I think I'm looking for something more like this: http://www.containerstore.com/shop/office/cordControl?productId=10000329. But let me know how it goes for you.
deaffob - Nice. I tried putting it in a special pocket of my backpack laying flat, and no damage so far. Still, I'd like to find a case if possible.
ricerocket - Cool, that looks cheap and durable. How well do the K550s fit in there?
harir - That looks real official. Keep in mind that the 50mm drivers and their earcups are bigger than most headphones. Still could work.
vinland - How could you? I'm trying to make the cable convenient without risking damage to the cable. But hey, different strokes for different folks, right?
So I guess now that I've seen what case options are out there, now I'm really looking for a quality cable turtle that can hold the thicker gauge cable on the K550s, preferably holding up to 6ft of cable.
Does anyone know of a cable turtle that's decently high quality? If I can't find anything else, I'll probably go with something listed on Amazon as I have Prime.