You can buy Sex and Bowls and Rock and Roll from…
Online: Amazon (UK), Waterstones, or The Book Depository.
Or on the High Street:

A bookcase that opens up to reveal a secret place beyond, like in the Scooby Doo cartoons.
at Waterstones
(click to check stock in your local branch first; if they’ve sold out, ask them to re-order it for you)
at your local independent bookstore
(if they don’t have it, they’ll be happy to order it in for you)
On your iPad, iPhone or iPod Touch:
from the Apple Store, here. £2.99.
On your e-reader:
Kindle version, via Amazon; e-book, via Waterstone’s. Both around £2.50-ish.
If you’re not in the UK:
See some international options here.
