Founders to be, take note: I worked with Jeff and David for a little over a month last year. The thing that stuck with me most wasn't their app (which is awesome by the way) but rather the way they treated me and every other team member. They were kind, gracious, wicked smart, and extraordinarily driven. They were always open to new ideas but never afraid to say "no".
If you're trying to figure out what type of founder to be, borrow generously from these guys.