But Kayak already has a really nice discovery interface... https://www.kayak.com/explore/ https://www.kayak.com/explore/ In fact, I often use Kayak to figure o

But Kayak already has a really nice discovery interface... https://www.kayak.com/explore/ https://www.kayak.com/explore/ In fact, I often use Kayak to figure out which airport I should fly into. For instance, if I'm traveling through countries X, Y, and Z and I don't care what order I visit them in, I can quickly check which one is the cheapest to fly into.