Here is a great plug-in that I have found for increasing traffic from Social Bookmarking sites. This Wordpress plug-in automatically bookmarks your site to Social Bookmark sites each time you post, including:

blinklist.com
furl.net
del.icio.us
myweb2
shadows.com
simpy.com
spurl.net
ma.gnolia.com
blogmarks.net
rawsugar.com
smarking.com
linkrolling.com
blogmemes.net
markaboo.com
linkagogo.com
feedmelinks.com

This plug-in avoids spam with a clever option which randomly selects ‘X’ sites for submission, so you aren’t spamming.

Check it out Auto Social Bookmarking