My podcast client supports BitTorrent. Is that widespread? This Amercian Life's podcast bandwidth costs them $150k/yr, but the only reason for them to serve every copy themselves is so they can count the listeners. So really it's the cost of their accounting, not their bandwidth. (Or it's the cost of people using lame download-only clients.)
Walking navigation should have a scenic option, based on public geocoded photos. Maybe it could try to guess if they are outdoor shots. You could even correlate photo clusters with historical weather data. Parks are good on sunny days, museums whenever. That might make for a fun data map, showing photo density vs weather over an area...