Robin Good: Headslinger is a web app which allows you to organize your favorite web sites into folders that you can easily scan without needing to navigate to each site.
You can also see what other sites other users are looking at and receive recommendations for sources similar to the ones you browse.
Free and without ads.
Try it out now: http://headslinger.com/
N.B.: To suggest new sites to be added to Headslinger go to: http://headslinger.com/submit/source/