Interestingly, Konica AR mount bayonet is almost identical to the Nikon F-mount. You just have to remember to turn clockwise to lock (F-mount is turned counter-clockwise).
This Vivitar Konica AR mount wide-angle that I picked up from eBay next to nothing fits surprisingly well on the Nikon D90. Nikon’s long flange focal length – typically an undesirable feature for SLR enthusiasts – has turned this 28mm wide-angle into an effective macro. The result is surprisingly satisfying. It captures amazing close-ups. The lens is sharp and easy to focus. Of course, there is no focus-to-infinity due to the aforementioned flange focal length.

Couple test shots:

*Please note: if you are attempting this fit, do it at your own risk. This particular combination has caused no damage to my Nikon but I’m not making any guarantees.