Thanks for the recommendations WDC.

I guess I was trying to address the whole social aspect -- what sites/directories/forums do other SEO experts use to build up their own and their clients' sites?

So while it is wise to spend time making sure everything you can control, internally, such as SEO, blogging, article writing, press releases, etc is up-to-par; there is a whole other aspect that can be influenced by outside sources/services and it would be worth your time to take a look at.