Thanks for that. I'll look those out.

The Lethbrige is daft-ish in that Von Daniken kind of a way but his theories on how large stones could have been transported by water are interesting and led to various experiments in the bath with plastic boats, ice cream sticks and margarine tubs full of sand! What is great about TCL is how intuitive his stuff is so yes there are some weird detours along the way. He's also offers a nice counter-point to Dawkins, Pinker and Mithen amongst others. Always good to keep your options (and mind) open!