I use RSS and would hesitate to winnow it down through the use of the tools suggested in this thing. If all I subscribe to would be things I want to read, why would I deliberately minimize what I get? Google Reader is my choice to manage RSS feeds to which I subscribe, and the way I've managed it is to remove those blogs or feeds that had either no action or ended up not being what I want to read.
I have faithfully read and kept current on all blogs and websites I've followed. They're the folks I enjoy reading about, their trials and travails, conquests and commitments. It's enough. Sometimes there's such a thing as information overload, and if I limit myself to these few folks, it's plenty for me!
I don't share a lot of bookmarks and don't care to tag them, and should I want to share a website with someone, I can't think of a more finicky way to do it than through Delicious. So if I'm happy with my RSS feeds, why would I want to sign up to follow Delicious? Is it the same thing, or different enough that I should check further? Hmm. Well, not today anyway.