Katy Guest: Crack the title, crack the code

Whosays you can't judge a book by its cover?

Thanks to two completely unassociated geeky millionaires, who have made their fortunes by hypnotising a willing public, this has been a good week for the viral email, aka the youtube clip that everybody watches at work because it is clever and therefore can't be considered skiving off.

First came the clips of psychology students demonstrating how Derren Brown might have magically predicted last week's Lottery numbers – proving it's amazing what you can sneak past intelligent people when they're concentrating on something else. And then there was Slate's automatic "Dan Brown Sequel Generator".

Plug in a city and a sect from the list on offer, "and our computer will do the rest," is Slate's invitation. The result is a title and a blurb that is spookily similar to something that Brown might write (only better). Entering the city "Ottawa" and the sect "International Olympic Committee", for example, generates a thrilling yarn built around "a secret branch of the IOC". Its brilliant title is "The Forgotten Rune." There are potentially hundreds of unliterary outcomes.

Slate is not the first website to mock Brown's formulaic writing in this way, but as usual, publishers have already got there first. Blindly stick an arm into this paper's books cupboard and a reviewer could pluck out at random a sinister and cultish number of Brown rip-offs. Titles such as The Lost Throne; The Mozart Conspiracy; The Alexander Cipher; The Notre Dame Cryptogram; The Vermeer Variations; Falling in Louvre; The Curious Incident of the Art Historian in the Night Time.... (Three of these are genuine titles.)

Choosing a book title is a profound responsibility. Jacket designers are clever: you can judge books by their covers. But nothing pricks the imagination better than a catchy title. Had Jane Austen's Pride and Prejudice been called First Impressions, as was planned, the world might never have benefited from nearly 200 years of Darcys. (Or from the latest rash of Pride adaptations: Pride and Prejudice and Zombies; Sense and Sensibility and Sea Monsters....) Would The Great Gatsby have become quite such a point of cultural reference had F Scott Fitzgerald stuck with his first title: Trimalchio on West Egg? Would a Catch-18 ever have caught on?

Book titles appeal for different reasons. The lovely anthology Snow Fruit by the poet Mary Maher still makes me taste a short-lived brand of frozen yoghurt lollies. There is a new popular science book that should be bought for its clever title alone: We Need to Talk About Kelvin.

Joanne Harris, who appears at The Independent Woodstock Literature Festival on Friday, writes novels that are desirable because they sound edible: Chocolat; Blackberry Wine; Five Quarters of the Orange....

Only a supremely confident novelist can break the rules of book-naming and still succeed – as Sunday's festival guest, Sarah Waters, will surely show. The title of her latest novel, The Little Stranger, has been used by three writers before her: Candia McWilliam 1989, Kate Pullinger in 2006 and Knowles Gaye in 1948. Fortunately, each of these books is distinct and impressive enough not to have needed a random title generator. Which is more than you can say for the Dan Brown clones.