Grumpy Old Bookman prompted me to have a look at Play.com, which he recommended, as an alternative to Amazon. And sure enough: good prices, including delivery, and apparently very good delivery times, especially compared to the times Amazon quotes as soon as you stray away from the bestsellers.
http://www.play.com/play247.asp?pa=navmain&page=front&r=home
I still think your local independent's the best bet, if you've got one, but failing them, and if, like me, you feel equivocal about Amazon, this looks worth a try.
Emma