There are lot of Social bookmarking sites and they give a nice traffic. But its really boring to visit every site and bookmark. But there is a nice , easy and quick way that you can make it in sec . I hope you have already understood. But if you dont know that then listen - its Onlywire.com.You can use them to Bookmark at 20 sites just with a click.What you need is to sign up those bookmarking sites. Then save the usernames and passwords to onlywire .But you will miss stumbleupon there. Just get a firefox extention.Best of luck.