[jQuery] How to tell if an item is "open"

[Dave Maharaj :: WidePixels.com]

I have 5 divs which can load content into them. I have added an on click add
class open. When the page loads initially none are open, click on one link
and the open class gets added but if another link is clicked i need to
closed the open tag.
 
How can tell jquery to look for an open tag if it finds on close it? (An
accordion style layout is not what I am looking for)
 
Dave