Social Bookmarking?

[SAWebay]

Social Bookmarking as a SEO Tactic!

A new kind of link building tactic is revolutionary to the SEO arsenal.
With carefully timed posting to these sites, exposure can work their magic
for the website owner and those concerned with SEO in creating back-links.

If you are a responsible site owner intent on creating back-links for
legitimate purposes then you can use software to "Automatically register and
submit metatags" (keywords) to hundreds of Social bookmarking sites
including CAPTCHA protected sites.

http://make-it-or-break-it.blogspot.com/2008/06/social-bookmarking.html