I’m trying to get my head around OPML right now, and it’s not going so well. I can see it’s worth for passing lists of non-time-based data (as opposed to RSS/Atom which is great for time-linear data lists). I’m just not sure what “Outlining” is right now … perhaps it’s just a little too late, too much working on a Sunday, and far too much NASAtv and following the Return to Flight.