Great point re destinations. You can actually do wildcard destinations right now, but it's just not obvious. We have an autocomplete function on the airport box, but you can enter anything you want. As you'll see on the RTW contests, we just entered "Round the World" for 'from' city and "6 Continents" for the 'to' city.

That said, we need to make this more obvious and probably tease out more adventurous use of this feature. Thanks for the feedback.