Any parent involved in a child custody visitation situation, should definitely take a look at this blog by Lee Rosen. http://divorcediscourse.com/2008/10/13/parents-meeting-at-the-halfway-point/
This provides the link to a very informative program called Meetways, which can point you to a halfway location based on the location of each parent. There are also many other useful ways to use Meetways, including finding halfway points for business meetings, etc.
Check it out!