Ask HN: What to do with several unused domains?

I have collected a number of potentially useful but currently useless (PUCU) domain names over the years, and while a couple seem obvious, I'm interested in opinions from others on what might be done with them.

Should I sell them, setup forums and wikis and hope the community self-polices (or forms in the first place), start blogging on specific topics, etc.

Thanks in advance :)

  actropolis.com
  arsauralis.com
  digitalrights.ca
  elite720.com
  fashiontouches.me
  firestrum.com
  innereyes.com
  iwriters.net
  kincms.com
  slashbracket.com
  spankk.me
  withanks.com