Yeah Twitter absolutely rocks. I recently had a post tweeted by both @AndrewWarner and @smashingmag [1] and it's now on page one for the search term "testing website" (when done on google.com.au). While the Twitter links were fresh it was page 1 on google.com, too an showing up as "news". This is a relatively new post with virtually no other inbound link juice on a site with not much other link juice and only PR of 3.

[1] http://www.decalcms.com/page/Testing_your_website_before_lau...