Hint: You can actually purchase buildings in each of the craters by locating the real estate agent's location. You can also call for a taxi, buy new "moths" (the crafts you fly), get new weapons and equipment, smuggle (illegal substances of course), be a vigilante (track down/kill wanted moth drivers for police) by visiting the police HQ and get the wanted list, salvage dropped merchandise (if you have a retriever drone), borrow money from loan shark(s), pay fines (to clear your record with the police), trade with various enclaves and shops, hire on as mercenary for one of the factions in the game, upgrade your computer systems in the moth by finding a software house, and much more...