I just got a sheath from Matt at Invictus Kydex.
http://www.invictuskydex.com/ Here's a photo from his website, but I have the same sheath for my RC-3MIL.
He makes some quality stuff that is well thought out. Very professional to deal with, willing to work with what you want, great communication and FAST shipping. I carry this knife in my pocket at work, and can reach in and "pop" the sheath off with my thumb.
Everywhere else I have a section of paracord that goes through the bottom of the sheath and loops around my belt. I stick the sheath in my waistline, and just grab the handle and pull for instant access.