I just turned spirecraft on for the first time and found the amazing spirecraft jumpship. With these, I can take worlds deep in AI territory (colony ship + 4 highest mark engineers + warp gates/turrets, only good for taking MK 1 or maybe 2 worlds.) They can also be used to kill all raid-ables that are not surrounded by huge piles of high mark ships, getting slow starships where you need them, and a hundred other tasks.
But the very first thing I did with them was to take 3 or 4, load them with scouts, and pop in for about .01 seconds on every single world in the galaxy. It was so quick and easy, I felt dirty afterwards. Did I just waste valuable asteroids for a not-too-important task? After all, I would have scouted eventually anyway with regular transports/raid starships, and I didn't really NEED the knowledge right now. I just feel so absurdly powerful, it'd be kind of comforting to hear that I did something stupid!