Current hedgehog fodder:<p>* Subscription as alternative vs. reducing life on newer technology. While being wasteful works in today's "make everything in China" world, long-lasting high-quality products that consumers "rent" make more sense than throwaway products financially and environmentally.<p>* Mining first-world trash. Third-world countries do this manually, but isn't commercialized in first-world.<p>* Developing products and services that rely on greater levels of energy than currently available. Energy, propulsion, etc. advances will be made more quickly in coming years.<p>* Undersea and underground living: greater use of heat, heat or pressure differential as energy sources, related horticulture, and mining - but there are problems to be solved: how do we adapt things we need for overground living to deep underground and deep underwater?<p>* Space, the final frontier, e.g. transport: SpaceX, distribution: Blue Origin, mining: Planetary Resources, touring: Virgin Galactic, propulsion systems: Orbital Sciences, etc. - but there are many niches to fill.<p>* Solving world problems of hunger, poverty, unsafe water, lack of shelter, violence - e.g. agricultural transforming, fair redistribution as a service, clean water as a service in the third world, alternative building materials, guns/tasers/billy clubs replaced with net guns.