With DarwinPorts installed, go to the Terminal and type in:
$ sudo port install man2html
$ cp /opt/local/www/cgi-bin/man.cgi /Library/WebServer/CGI-Executables
When done, make sure you have enabled Personal Web Sharing in System Preferences -> Sharing. Then point your favorite browser to http://localhost/cgi-bin/man.cgi, and you've got browseable man pages! They even link to one another.
Even better, if you use Quicksilver, add a bookmark for your man pages by using this...
http://localhost/cgi-bin/man.cgi?section=all&topic=***
...for the bookmark. Name it man. Now you can easily trigger Quicksilver and then type man [Return] some_unix_app [Return] to get the man some_unix_app page immediately.
[robg adds: I tried to duplicate this tip with Fink, which also has man2html available. It didn't, however, include the CGI. I downloaded that separately from the man2html homepage and edited it to match my setup, but still no go -- the CGI would run, but the returned man pages were blank. I'm sure it's something simple I've done wrong, so if anyone can correct me, please comment...]

