I use Bloglines as my RSS aggregator. I have a widget for it in my iGoogle home page and check it every day. I have divided my feeds into categories -- 23 things on a Stick (for blogs of others doing the 23 things), book reviews, adult authors, YA Lit, Kidlitosphere, Work, and People I Know. I have 99 feeds. Some days I just skim the new posts. Other days I have time read carefully.
The only feature I have used so far is the bookmarking and tagging my bookmarks. I did spend some time today cleaning up my tags to make them more uniform. The main problem I see with social tagging is the lack of consistency. Without a controlled vocabulary, ten people can tag the same site ten ways at least. How can you search? I have trouble finding my own bookmarks sometimes because I don't remember how I tagged them.
I added a badge to my blog to let people know I use Delicious. I have taught other staff members and sixth graders about it. Delicious is very valuable for anyone who doesn't always use the same computer.