So I do something perhaps similar to Bush's trail idea and perhaps not. I use google bookmarks to build my own set of links for a number of given topics (tags). I've put the javascript for adding as bookmark into a bookmark item so throwing the URL to something interesting and tagging it with subject tags relevant to me is as easy as selecting a menu item. To date I have over 1359 tags. For a given tag, say MPLS, overlay transport, civil war, central african precolonial women's rights, or hubble pics, I end up with a list of links to documents about that topic interesting to me. For the most part I keep the tags narrowly focused and nearly always have multiple tags per link. So the tags roughly correlate to trails, although obviously not completely. But, as I understand Bush's thinking on it, kind of.
If you have a google account, you can use it at bookmarks.google.com. The web interface is primary, but if you have your bookmarks bar visible, you can drag the 'Add Bookmark' link to your toolbar, and it will place a button there that when clicked will popup a window that will add the URL of wherever you were when you clicked it to the page at bookmarks.google.com, complete with fields for title, notes, and tags. So each person's bookmarks.google.com page will have a list of tags and recently added bookmarks. It's very straightforward, and reminds of Bush's trails idea.
