I know some people will spend a decent amount of $ on their K3 case, but I decided to take the frugal path and order some off of eBay for roughly $10-13 CDN each.
The first pic is of the cases side by side.
The 2nd pic is the case from SmartDigitalGear. The case itself feels fine and the padding is decent but the bottom row of the K3's buttons are hidden if you have the K3 sitting properly in the case. U can either push the K3 up a bit (as I did in the pic) or just press the hidden buttons beneath the "leather". The D-Pad is trickier to use unless you push the device up.
http://cgi.ebay.ca/ws/eBayISAPI.dll?...=STRK:MEWNX:IT
The last pic is from Besthoo Store. I use this case. The K3 fits perfectly and the padding is fine. You can't fold the front cover all the way back and have it sit flush as you can with the case from SmartDigitalGear but it's a minor issue.
http://cgi.ebay.ca/ws/eBayISAPI.dll?...=STRK:MEWNX:IT