The link to the Backyard Chickens article is the one I also found and very useful to keep as a bookmark.
I use small tubes (25g) of Activon Medical Grade Honey. The price varies where you buy it from and I usually pay around £3.50-£4.00. A tube lasts 90 days after it's been opened and a little of the honey goes a very, very long way. I do use Sudocrem, mainly for scaly leg, but the honey is a completely natural product and is used on human wounds.
The post on Amazon will tell you a bit more about its uses.
http://www.amazon.co.uk/Activon-Medical ... B003O31U86" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
Manda's right about the focused spot/scab in bumblefoot, but I've also had scabs on several of my girls' feet that turned out not to be bumblefoot just to frighten me!!