I just went with the Case Logic PLTK-10, about $15 from CompUSA... it's just a "snap over the belt" style holster, and the 6k sticks out the top by about 1/2 an inch, but it's a) cheap, b ) attaches to a belt, c) fairly unobtrusive (as unobtrusive as the 6k CAN be), and d) allows easy-in easy-out, so good for occasional "grab it and go" use.
HereDisadvantages: no retention mechanism. The thing comes with an elastic loop on the inside that's supposed to stretch over the top of the unit and hook onto a metal hook on the back. But the 6k is far too big, so now you have a bit of elastic rubbing on the unit, and after several months there's a noticeable (although not heinous) scuff on the plastic fold-over screen protector. I may just cut the elastic off and see if that helps.
In general, though, it's working very well for $15.
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