An OpenBSD advocacy article led me to a mailing list posting on how to get Flash playing transparently in Firefox on OpenBSD. You could get Flash (and other clunky media formats) to work on Unix-like platforms that Adobe doesn’t support for some time now, using a combination of players in packages and nearly random hacks in Firefox. This process makes everything simple, however.
I’m using 4.9/i386 and mozilla-firefox-3.6.13p3.
Set a package path in your shell. A few tests with ping and traceroute showed ftp3.usa.openbsd.org is my closest mirror. I use tcsh, so my .cshrc has:
$ sudo pkg_add -r gecko-mediaplayer
This installs a whole bunch of packages for playing not just Flash, but other complicated media formats.
Browse to https://addons.mozilla.org/en-US/firefox/addon/flashvideoreplacer/ and install the plugin. The plugin handles replacing Flash with appropriate third-party players from packages.
Restart your browser. And everything just works.