1. A user-interface method of selecting and presenting a collection of content items in which the presentation is ordered at least in part based on analyzing activity associated with content items having descriptive terms that describe the content items and promoting the presentation ranking of content items associated with descriptive terms that have an increased level of current activity, the method comprising: providing access to a set of content items, each content item having at least one associated descriptive term to describe the content item; receiving input entered by users for identifying desired content items; in response to the input entered by the users, presenting corresponding subsets of content items to the users; receiving actions from the users selecting content items from the corresponding subsets; analyzing the selection actions received from the users to detect an increased level of current activity relative to a normal level of activity associated with the content items selected by the users; selecting and ordering a collection of content items based on promoting the ranking of content items associated with descriptive terms that are associated with content items that have the increased level of current activity relative to the normal activity level; and presenting the collection of content items to at least one user.