In a tribute to the late founder of HowStuffWorks Marshall Brain, we chose one of his great articles. Learn all about how your phone knows how to get you around without bumping into stuff or running people over in this episode. Thank you, Marshall.

Selects: Mangroves: Nature's Best Tree?
44:31

How the Kowloon Walled City Worked
41:27

Short Stuff: In-Flight Entertainment
12:23