I'll ignore that comment Bazza (specially as I kerbed my wheel badly driving home from work!)
With minor kerb marks, get some fine sandpaper and go over it until it's smooth, then touch up with some silver paint (can buy at Halfords, pen size pots but buy a fine brush too). Once it's dry you can then go over it with a bit of laquer. This works well on minor marks, but anything more serious get refurbed by the professionals.