One of the most useful web 2.0 tools I use is RSS. If you've been even a little observant over the last year you've seen the icon here on about every website and blog you come across. RSS essentially turns access to online content on its head by bringing information you subscribe to directly to your web browser. Previously I had a series of bookmarks I checked regularly and accessed the information that way. With RSS, a single click of a button in my Sage feed reader brings me the latest content from about 20 different sites I like.
If you have ever felt like there are too many good websites out there that you wish you could keep up with, then get an RSS reader and bring that content to you all at once rather than fetching it a site at a time. It will let you sift through a much larger amount of content very quickly.
The flip side of this is that you want to get RSS on your website if you don't have it already. As more indivduals become personal news aggregators they will rely more on RSS and visit websites less often. As of last fall the number of people using RSS was still low according to this article, but RSS is growing and there's really no good reason for you not to incorporate it. If, however, your target is highly wired...get RSS ASAP.