My son, aged 8, was in danger of Giving Up Reading until he discovered this wonderful book - having raced through other magical tales by Eva Ibbotson, Tolkien's Farmer Giles of Ham and Harry Potter. He bascially won't read anything unless it has a dragon in it, which is why we fell on this with such relief.
The story, about a thoughtful, polite boy born into the Hooligan tribe of Vikings, who have to capture then train their dragon by yelling at it is not only very funny but has good things to say about the importance of jokes, persuasion and daring to stand up against the mob. The audio version, read with enormous verve and featuring terrific music and sound effects as the Green Death rises from the sea-bed to devour the tribes, is absolutely spell-binding. I can't recommend it too highly, especially for long journeys. More, please!