Here's one more example of the aerial photos anyone can get at
TerraServer. This one is at Tijuana, Mexico-San Ysidro (bottom),
California, USA (top). You can see the boundary from left to right.
What I like about looking at this and other photos is noticing the
different land uses in similar cross-border regions. There are also
a few instances where there are parallel roads, and bi-national
houses and other buildings. SE of Vancouver, BC, Canada, the south
side of Zero Avenue forms the boundary between Canada and the USA
San Ysidro-Tijuana
http://terraserver-usa.com/image.aspx?t=1&s=11&x=1243&y=9001&z=11&w=2
Surrey BC, Canada-Blaine, WA, USA
(Zero Avenue in Canada on top of photo)
http://terraserver-usa.com/image.aspx?t=1&s=10&x=2689&y=27138&z=10&w=2
http://terraserver-usa.com