RE: How does the B2 fly?
masae is right, they do have split spoilerons at the wing tips to control yaw.
Here is a pretty good link with pics.
[link=http://www.richard-seaman.com/Aircraft/AirShows/Edwards2005/B2/index.html]http://www.richard-seaman.com/Aircraft/AirShows/Edwards2005/B2/index.html[/link]