Saturday night, my friend Steve and I went to the Berkeley stop of Dave Winer's OPML Roadshow. I wrote about it on my OPML blog. While Winer gave his presentation, Steve downloaded the OPML Editor, installed it, set up his OPML Blog at opml.blogs.org/ari, and liveblogged the remainder of the presentation.
ActiveRenderer was a plugin for Radio Userland which was really nice, and people who saw my Radio blog when it had expandable/collapsible days and weeks of archived posts were really impressed.
UPDATE 8/30/2005: See Tim Bishop's site for the most complete accounting of links from this event.