Umm..Social Bookmarking

What I have come to notice as I read more and more about Web 2.0 is that there are a lot of fancy terms for the stuff we do everyday. When I think about tags the first thing that comes to mind is Facebook. I tag the pictures of my friends and I tag them in notes. I never really thought about using that technology outside of that realm. As far as social bookmarking I also do this everyday whether I intend to or not. From my understanding it is a way to connect the things you are interested in all together and also share them with others. I wonder if an example of social bookmarking would be when you find a interesting item online the site has a "share this item" button and you can email your friends the image. Or how about emailing youtube links to each other? Does that count?I personally never use my bookmark or "favorites" on my computer. I have two sites saved as "faves". One site is called drinkmixer and it has every drink recipe known to man and the second is the link to the class wiki because I can never remember how to get to it. So on one hand I can see how there is a need for these large bookmark sites. In most cases when you are surfing the web for information you only want what is relevant to the search and I guess social bookmarking helps to achieve that.