A method, apparatus, system, and signal-bearing medium that in an embodiment represent previously-accessed data items as nodes in a tree or trees and display the tree or trees with the access time on an axis. The root node of a tree represents a data item accessed via an address entered by a user while a child node of the tree represents a data item selected from a parent node of the child node. In an embodiment, data items that were displayed in the same window as their parents have different connectors between their associated nodes than do data items that were displayed in different windows from their parents.