The world's bellybutton by Tanya Landman

Walker Books 2007.
(Age 7+) William Popidopolis sometimes wishes he had an ordinary name like Smith, but his Greek connection proves very exciting when, while holidaying in Greece, he is approached by a large swan who engages him in conversation. The swan turns out to be Zeus, the king of the gods and he persuades William to help him in a race against time to retie the knot that secures the world. With a trip to the Underworld and a chance encounter with his distant ancestor Odysseus, William, who is slightly lacking in the confidence department, discovers reserves he never knew he had. Coming up with an ingenious plan to defeat the Gorgons and retie the knot, William embarks on the adventure of a lifetime.

This is a fast paced short novel which will engage newly fluent readers and would also be suitable to read aloud. Chapters are short, and usually finish on a cliff-hanger, action outweighs description and the plot is straightforward and exciting. William is a likeable character and children will identify with his anxieties and uncertainties and delight in his success in conquering his fears and saving the world. Ideal for confident readers, both boys and girls aged 7 plus. 
Claire Larson