in 6 hours. Crossing national borders by foot is always fun. I remember being shoved off a bus in the middle of the night to walk the border between Uganda and Rwanda. Walking in a bizarre no-mans land where you have no rights, no protection, no identity until you cross the line again, to become a citizen/foreigner. The arbitrary lines that create "nations" become more and more real as we base our identity on these false nationalities. Here is a nice overview of these issues. But I recommend walking the border, Tijuana is wonderful. Just watch for this.