My out of season stuff is stored in plastic moving crates in a closet under the stairs:
http://www.flickr.com/photos/2.....519275274/
I also have some items in under-the-bed storage, but I have found no matter what storage you use under the bed, it is apt to get dusty somehow. So I just keep my out-of-season "gear" there (i.e., my winter running clothing and winter pj's).
About three times a year, I haul everything out, and do a closet rotation.
I have very little closet space too; if you hit the browse button you'll see further pics of my closet arrangement. Coats - I didn't take a photo of those. Leather coats are in my closet. Out-of-season coats are in the hall coat closet. In-season coats hang on hooks in the back hallway, which nobody uses unless they are going to the basement. My dad made me a custom shelf with numerous hooks that lines the entire hallway, for ample coat storage. We have four people in our house so we have a LOT of coats, but this system seems to work okay.
