Being in the market for a new EF100-400mm lens, I've browsed countless sites looking for the best deals (UK Canon Lenses seem to cost the Earth right now), and I thought I'd list the most helpful below, for anyone else in my position:
The first, CheckoutSpy.co.uk found me a deal on a EF100-400mm for £1175 including P&P:
http://www.checkoutspy.co.uk/browse/111/electronics/photography/digital-camera-accessories?filter[acctype]=26026&filter[cameramodels]=26035&keywords=100-400mm&sort=0![]()
Another site found me one for slightly more, at £1190 - but this site features handy graphs showing pricing trends etc - all makes for very depressing reading (in March last year this lens was £909)! 
http://www.camerapricebuster.co.uk/prod37.html![]()


