I think that RSS feeds are just the greatest and use the Google Reader on my iGoogle page to read them. They quickly mount up, and with the advent of Twitter, I've found that my use of RSS feeds has dropped off quite a bit. Instead, I'm find that more and more the late breaking news, cool sites, announcements, useful tools, and links to significant blog posts are being posted on Twitter -- and from there it is a quick link to the item.
I also use Friend Feed which allows me to see what people are posting to their delicious account. That is very handy to know what others have found significant and often that is a great way to check out sites that are of interest.
Finally, regarding Delicious, I have found that placing people in my network allows me to look at their Delicious activity and I find many shared interest there. Since my neighbors and several friends got Blackberries at about the same time I did, it has been fun to see what they post on Delicious regarding using a BB -- an easy way to share info.
I'm a huge fan of Delicious and don't know what I would do without it. I use to keep track of all kinds of things -- personally and professionally. It's useful for very simple things, as well as for very complex topics (the Recovery Act funds, for example). And, new topics crop up every day that I want to remember and track.