I'm totally engrossed with Ruby these days, so I'm thinking about switching to Ruby instead of PHP. I'll probably use Sinatra as the development framework.
UPDATE: Now that I'm working full-time as a Ruby on Rails developer, that is my number one focus. While I use numerous versions of Rails at work (1.x, 2.x, and 3.x), I mainly use Rails 3.1 in my open source work.
As such, I've researched open source forums in Ruby on Rails (as engines) and I've found Forem, by Radar. It claims to be the best forums software, ever, and it just might be.
Actually, its pretty simple, but that's what I like about it! So I'm not sure what will happen to PhunkyBB. I'll probably try to port some of the useful yet missing concepts of PhunkyBB into Forem. Actually I already started - I added a position column for acts_as_list positioning of forums within a category when I ported the NeoCarz forum to Forem.
I'll keep the content from PhunkyBB around for historical purposes (I don't like to let open source projects to bit-rot), but I'll merge it into one of my other sites, probably Docunext. A couple other ventures I poked at have ended up at sub-domains there - at least I'll save the $10 per year domain registration fee!
I'll also likely switch to using Jekyll as the content manager for PhunkyBB. That or Middleman.