I really liked the Super Program finger grip, and was kind of bummed that the older K-series cameras didn't have something similar, and they really needed something to help them feel better in the hand. So I bought a set of
Flipbac grips.
I bought one for the front of the camera, and one for the back as a thumb grip, and it now feels really natural. I have a K2 and K1000, so I bought three in total. They trim real easy; they're made of soft rubber, and cut straight and clean. I trimmed up the front-mounted ones just a little to fit nicely on the camera, and trimmed a half-inch or so strip for the thumb grip.
The adhesive works "good enough," but probably not great for long-term use, and definitely not for heavy use, especially in warm weather. They start to slide around a little. I haven't secured them on with Gorilla Glue yet, but that's my plan.