OPath is a method by which you can link directly in to OPML at the node level. It's very simple to use, and it moves us a step closer to the distributed directories idea that Dave has pioneered.
I've got some pictures explaining OPath - before and after.
OPath uses PHP's excellent Cache_Lite library in order to minimise the hit on the owner of the OPML file.
If you are using the OPML Editor, I've written a little script to use OPath in the OPML Editor.
Setup
Enter a URL for an OPML file below in order to find OPath nodes.