I said above that I would add a section to my website on BECs. Ive just looked and noticed that there is already a whole page about them there already!

Its here: http://homepages.which.net/~paul.hills/Emc/Bec.htmlhttp://homepages.which.net/~paul.hills/Emc/Bec.html

Just goes to show how large my site has grown that I cant remember whats in there!