I bought a chip repair kit from Halfords. Costs £10 and you get the Primer, Paint and Laquer. You just clean the stone chip up, fill in with primer, leave for 24 hours to dry, fill with paint, and then leave again for a further 24 hours. At this point it says to use the laquer, but I didn't, which made it easier for Si to blend the paint in with the surrounding area, and wet sand and buff back up.
