I just got a 2011 250 Ninja. The first thing I noticed while riding was I have no clock! I searched and found many $30-50 addon's. Didn't really care to spend that much. I used a simple conduit hanger and a #8 32x1/2 screw to mount my otterbox holster to my bike.
1. You'll need to have an otterbox case.
2. take your drill and put a hole in the belt buckle of the otterbox holster.
3. put the screw through the conduit hanger and the buckle adding your nut at the end of the screw.
4. put the conduit hanger on bike and screw it down.