1. In a computer system having a display and a memory for storing items with metadata properties, a method of filtering items, the method comprising: providing a plurality of display objects on the display that each represent one or more items; filtering the items represented by the display objects based on a filter term; and modifying the display objects that are provided on the display so as to represent the items that have the metadata property that corresponds to the filter term in response to the filtering of the items, wherein one or more of the modified display objects comprises a virtual folder.