We're working on a new concept idea too (isn't everyone? i'm sure "myspace for left-handed-black-blind-jewish-lesbians" is completely original) --- but a couple

We're working on a new concept idea too (isn't everyone? i'm sure "myspace for left-handed-black-blind-jewish-lesbians" is completely original) --- but a couple observations: 1) Like you said, we constantly work to make our app as intuitive and documentation free as possible. I've done quite a bit of UI design, but I'm still surprised users' obliviousness -- "just launching" is always quite humbling! 2) People usually just click around until they get stuff to work. Create a UI thats a won't punish people if they screw something up. 3) Anything longer than two sentences won't be read anyway -- we've found brief contextual help pretty effective. 4) Don't get discouraged about iterating over and over and over on designs until stuff starts to gel. I'm preaching this to myself right now. Best luck.