(1) Though I don't recall where, I remember reading that with Roth IRA's, it wasn't a question of what you can invest within them, but of what you can't. So, what are the investment vehicles that can't be invested in Roth IRA's?

(2) How valuable is the ability to withdraw initial contributions to Roth IRA's? From what I've read, it appears that the withdrawal of contributions is not adjusted for inflation.