I have used Twitter mostly and now I'm starting to use Pinterest and Friendfeed.com. I really like Pinterest. I have not used Digg in a while because it's harder to keep stories at the top of the list. Because I don't have many hubs, I have not promoted as much. However, I have used my Hubpages for backlinks to my Squidoo lenses, (http://www.squidoo.com/lensmasters/The_Idea_Gal). Perhaps you can link from Squidoo back to Hubpages. Also, SheToldMe.com is not bad for a little traffice spike. Good Luck!