I'd like to recommend 2 plug-ins for Leopard to enable Quick Look to be able to show more detail.
Right now if you do a Quick Look on Folders or Zip files, all you see is a generic folder. But I've downloaded 2 plugins that enable me to show a detailed look at whats inside either a folder or zip file. Get the plugins at www.qlplugins.com. then install them in the quick look folder in your main library. Then relaunch the Finder- option + right click the finder icon on the dock. From then on you'll be able to do a quick look inside folders and zip files.