I love 
Wikipedia and use it as my primary point of reference. Many people might not know that it goes well beyond your standard encyclopedic reference. One of my fav’s is using it to refresh myself of books that I’ve read in the past, but can’t quite remember the plot details. As Ilya suggests, it could well be a Cliff Notes replacement.
Ilya Lichtenstein suggests 8 other uses over at Neomeme.
Adam Pash over at Lifehacker.com posted a review of a 
new web based RSS reader called Fastladder. Based on his review, I decided to go check it out. While the integrated search feature is cool and something that I would really like to see in Google Reader, I prefer having a “river of news.” I enjoy being able to read based on time posted versus having to read an entire blog before moving on.
In addition, I am not a huge fan of keyboard shortcuts. I know they are the holy grail of efficiency, but I like being able to click on next story to move on. At Fastladder you have to keep scrolling or try to remember what the hot key is.
For me, for now, Google Reader is still tops.
Since I rarely update this blog, I am guessing that this level of addiction is based on how many blogs I read and how much time I devote to reading them.
On that subject, I have to give a big thumbs up to Google Reader.
There are plenty of other news readers and RSS aggregators out there, but Google Reader makes sense for me. I already use Gmail, Google Docs, and Google Notebook.