To celebrate the release of Terry Pratchett's 37th Discworld novel, "Unseen Academicals," Harper-Collins has placed the first Discworld book online for free.

The Colour of Magic introduces the Discworld as we know it, with Rincewind the "wizzard" shepherding about the Disc's first tourist and his homicidal luggage. It's much more obviously a parody of fantasy novels than the later, more satirical books became, but the style and hilarity are there in big lumps.

"Unseen Academicals" is out in hardback, as low as $14.95 at Amazon, although you can get the ebook version for just $9.99 at Barnes & Noble.