Here's a link to a lot of info and FAQ's on batteries. I especially liked the "Battery Myths" section (no, setting a battery on concrete will not cause it to drain). FAQ LINK HOME PAGE
I knew that one was false from being in the auto electrical business before but you still can't make people believe it.
Alot of good info in there, specially correcting me on some of those myths! Good to know, thanks Rick
Now I need to go out to the garage and remove all the pieces of wood out from underneath my spare batteries.