Over on the Bootstrapper site, Christina Laun has posted a list titled Better than Monster: 50 Free Places You Can Post A Job Online and Get Top Talent. Her list includes some well-know alternative sites like Craigslist, and some other niche job locations.
Recruiters should check the list to see if you can use some of these to expand your posting circle.
Candidates should check the list for new postings not on the majors.
Unknown factor: Does the Indeed search engine go out to these sites?