Just received my copy of Chris Andersons "The Long Tail: How Endless Choice Is Creating Unlimited Demand" after monitoring his blog and waiting patiently for months for him to finish it.  As you will have seen from Martin Dinhams e-consultancy.com interview the other day we are strong proponents of long tail theory, thankfully I have the book and the concept has some life left before the search engines do their best to make the tail completely unaccessible for advertisers.