I do a lot of pocket holes & noticed my Kreg bit was getting dull so I bought a new one at the local Rockler. While there I asked if they can be sharpened. It turns out you can mail the bit to Kreg (cost about $1.75 for postage) & for $4 Kreg will sharpen it for you. I thought this was a pretty good deal (a new one was $17). Just got it back today, about a week turnaround.
Dennis