After my initial apprehension at possible vandalism issues in trailfire, I’m beginning to think that trailfire supplies exactly the features that digg has been missing. This became clear to me when I had a look at the user pages on digg, and noted that in spite of diggers providing, in essence, a public service, they are not granted personal userpages in the way Wikipedians are. All they get are some stats and a link to their home page. There is a lack of efficiency: why should I have to click again? Why not at least provide a preview of the userpage? (Incidentally, there is a WordPress plug-in that does this.)
In the same way, digg does not provide a way to digg a site while viewing it (although this can probably be done if the site itself has an appropriate plugin*). Trailfire does.
* If you need to know, you’d use the referral url to find the correct digg item, and redirect the user’s click there; how easy this would be depends on whether you need to supply the user’s ID, and how you can obtain it; digg of course could block any such attempt if they wished – but why would they?