Both my wife and I are happy KIN users so I thought I would share some information that might be useful to others about the KIN phones. Note that I am not attempting to replicate or duplicate the official support pages, but instead share additional information. As things come to me I'll try to add then to this page.
Caveat: this page is not condoned or endorsed by Microsoft or the KIN team. Your mileage may vary. Void where prohibited. Etc.
The built-in hands-free car kits we have used successfully are the Sony Ericsson HCB-30 (very old but that's what I have) and the Parrot CK3000. Although the KIN supports audio-over-bluetooth, neither of these do as the S/E is too old and the Toyota that has the CK3000 is incapable of accepting a useful aux input (can you believe it? Toyota's in-car-audio story has been broken for a while).
We love the iGo range of chargers and cables, and the A97 tip (micro usb) works fine on our KIN ONEs. On a KIN TWO (which neither of us have) it is a tight fit though. With the splitter we can charge both phones with a single cable. We can also charge our Zunes with a different plug of course.
I don't have a part number but Verizon stores sell a hard case for the KIN ONE. I have the transparent one but noticed that the hole used for the external speaker is covered up, greatly reducing the ringtone. I carefully used a Dremel to make the hole that someone forgot to, to make sure I can hear it when my wife calls :-)
I don't usually edit comments on my blog but I will be making an exception here. Please don't rant about KIN or anything else, and please don't ask about things until you have tried the official KIN help pages first.