> ad hoc voice-based social networks based on proximity

Congratulations on reinventing the CB radio.

> "Why can’t I manage waste pickup from an app? What might a re-invented garbage truck look like?"

Taiwan does this the other way round: https://www.huffingtonpost.com/2012/01/09/taiwan-garbage-tru...

In this case, it's a municipal service that people don't fundamentally want to pay for and it's hard to make "premium". So you'd have to sell to municipalities on cost.

> The buzzer for restaurants, why can't it have a screen to display menu, or let your preorder?

The JD Wetherspoon "order at table" app basically lets you do this.