If you look at this blog in a browser you'll notice a list entitled 'interesting links' on the right hand side of the window. This is actually fed from twitter via twittermail, and I've been doing this as an experiment for just over a month now.
As an experiment I think it's quite successful, if only for me to (a) keep a list on interesting links in my sent mail and (b) share interesting things I've been reading with anyone interested enough to follow this blog.
Of course it doen't have to be twitter and twittermail, various other microblogging services provide the tools to create a similar effect - here it's twitter and twittermail purely because I found the correct off the shelf tools in their software ecology.
Personally I think this anonymous sharing model is more useful than the social networking 'share with friends' closed group model - it allows people who may be interested in a topic and who follow your blog also to follow the links you find interesting. Social network providers want to of course use the links to help add value to people who are part of the network to keep them hooked, or sell targeted advertising to or whatever.
In fact it's probably almost worthwhile also providing a separate rss feed for the interesting links as it's not beyond the bounds of probablity that someone finds the collection of links more useful than the original blog.