Piece on typical mistakes made in the sign-up process. Mostly common-sense points—Mistake #8: Not Telling Users How You’ll Use Their Information—though … gulfstream/2374
Dr Nic » Zero Sign On - 1 better or Infinitely better than Single Sign On?
single sign on works--now!--via myopenid and client certificates (don't seem to be able to password protect single certificates, though)