This demo uses OpenLayers.Control.TimeSliderBar with OpenLayers.Layer.TimedPointTrack. The track is created from GeoJSON, and the vertices can be tracked based on their temporal attribute.
The above input box allows the input of a URL to a GeoJSON file. This can be local to the HTML page -- for example, entering 'json/track1.json' will work by default.
The example shows a track, displayed as a line. The time-select control in the lower right can be used to select a certain time for the displayed layers, either roughly by dragging the bar, or step by step pressing the + and - icons.