After installing Leopard, I noticed a missing feature with Smart Folders: I didn't see any GUI-based method for changing the location (path) for the Smart Folder function. In Tiger, there's an "Other" button in the toolbar which allowed for the specification of a path -- but that was removed in Leopard.
After some digging, though, I realized the problem: I was using the File » New Smart Folder menu item to build my searches. Using the menu item, the only options for search location are the computer, the user's home folder, and the Shared folder. However, if I use File » Find (Command-F) instead, then the Smart Search comes up with default search locations of the computer, the currently-selected Finder folder, and the Shared folder.
So in order to search a specified location in Leopard with Smart Folders, you must use Command-F to start the search; the menu item is ba...