The Panther version of IB includes some NSCell subclasses in one of the palettes, including NSPopupCell, NSButtonCell, etc. However, I've not figured out how to use them in IB.
I've tried dragging them onto NSTableViews and NSTableColumns, I've tried double clicking them, I've tried dragging them into the main window. All to no avail.
I'm sure it's obvious, and I'm going to kick myself when somebody gives me the answer, but how am I supposed to use these in an NSTableView in Interface Builder?