We need to update our documentation/FAQ for various non-standard features, but in the meantime we'll use this thread.
Kison has recently stepped in as lead code admin, and has been implementing some things that the group has been working on over the past few months (as well as showing off and taking on new features).
Recently added features include the ability to search PMs (just activated for all users in the past few minutes) and countdown tags (produces a clock which updates on refresh, very useful for deadlines and for those confused by time zone differences). We've also had a few fixes for bugs/minor annoyances (see threads marked "FIXED" in this forum).
If you have any problems with a new feature, you can report it here or PM me or Kison. If you have suggestions for new features, please start a new thread in Site Ideas.