Inspiration style synergy is all very interesting, but I haven’t touched so much on how it works as that it works. On the other hand, I’ve been fortunate enough to be in a group that’s practically powered by it.
The primary group I play in currently has four members, counting the GM, though we’ve had more before, and only three of us are from the beginning of the game. Our GM is an event-based conceptual, strong leanings in both directions; his worst element is setting, and his worst form expansion. Then we have me, the character-based expansionist weak in event. And then there are our two others—one’s event-based, one’s setting-based, and both seem to be somewhere between conceptualist and mechanist, often adjusting to balance each other out depending on who got which idea first.
Of course, there’s a lot of sharing of ideas going on. Some of it is cooperation between GM and players; the GM conceptualizes things, and often asks for suggestions from the rest of the group. Not long ago, the request was for thematically appropriate powers for some people, PCs and NPCs alike; I got the pattern from the GM, figured out things that seemed visually/thematically appropriate, and handed them off to the rest of the group for numbers maintenance.
But the greatest synergy is between the players. When you’re playing in a game, as opposed to running it or writing a story, the elements of inspiration don’t matter as much; it’s all about form. And between the three of us, we usually have every form we need to. As one of the others pointed out, “Usually I get crazy ideas and he figures out how to make them doable. Or he gets crazy ideas and I figure out how to keep them from getting too absurd while keeping them possible. Then you make pretty pictures of them.” It’s not always quite like that; sometimes there’s a definite path we need to take, and then I’m the one who makes the first move, twisting logic into a good answer and then tossing it to them to make feasible mechanics out of. Other times we want to write powers, and if it isn’t one of them coming up with numbers and wanting a picture, it’s me coming up with a picture (and a few numbers; I think my weakness is concept, not mechanic) and wanting a hand balancing the numbers. Either way, the best results are the three of us working together.