Indexable Social Bookmarking sites

There are many social bookmarking sites but most of them do not get indexed at all. I even didn't get indexed pinterest profile even i moderately back linked it.

So far i have found just 4:
http://newsmeback.com/story.php?title=how-did-brains-evolve
http://youmob.com/
http://friendfeed.com/
http://www.last.fm/

Are there more such sites? I do not care if it is ******** or nofollow i need anything that doesn't look spammy for anchor diversity because I wanna use exact and partial anchors for PBN links.