I'm hugely enjoying the meticulous research into the best fruit varieties to choose for our 35m of south-facing wall at Abbey Gardens. We will plant circa 30 trees to be trained as single stem cordons, this winter - date TBC.
I found this appletastic site - OrangePippin.com which aims to get users to catalogue their apple trees for an all over the country (and world!) map. It has a way to go but I like the idea.