John Conyers, excellent Congressmember from Detroit, MI, is circulating a petition, asking for answers about the Downing Street Memo.
His website is here; he also posted it at Kos, among other places.
Read, sign and post.
Don't ask whether or not it will do anything. Remember what Gandhi said. (And by the way, that's the correct quote. It is often misquoted as "...may seem insignificant to you". The original statement is not conditional.)
Please: read, sign and post.