Are you talking about a locker you want to put at your barn...or some place to keep/organize your tack at your own home? My barn doesn't have a specific tack area. The BO has a shed thing (like what you would buy at lowes)...and so does another boarder, but I did some pricing of something big enough for my two critters and all of our junk plus feed, etc...I could buy a saddle for the price of one of those!!!
What I'm planning on doing is getting a shelving unit from Lowes like this one
I'm going to bolt some wood to the sides to attach saddle racks and hooks for bridles, halters, reins, etc. There is a smaller one than this, but I'm really liking all of the space (I have a lot of junk and this essentially will be my tack room). The only thing I haven't figured out yet is what I'm going to do with my saddle pads. I think I may just keep them on the top shelf (I'm tall) folded in half after letting them air out to dry any sweat.
I haven't actually done this yet...it's just the idea that's in my head right now. I'm pretty sure this is the way I'm going to go though. My husband's getting tired of our guest room being used as a tack room. :)
Edit: I meant to also say that of course this can't be locked up unless you completely enclosed it, took out a shelf to make room for a saddle or two and put doors on it. Um...no. I'm not doing that...this is going to be placed in my garage. :)