We've been aware of the evaluation criteria inside Google for a long time and how a website can be subject to a more thorough going over than that purely delivered by technology, but for the rest of the world Googles own lawyer officially let the cat out of the bag recently with his "Google is constantly evaluating Web sites for standards and quality, which is entirely subjective" comment. 

I'd always thought they recruited raters via Universities, but if anyone else fances becoming an evaluator / rater themselves as long as you have a batchelors degree or equivalent I bet quoting Job Ref: KIR070606  to Kelly Services will open a few doors ;-)

Temporary, home based workers to work on a search quality evaluation project for a well known search engine company. - Verbally confirmed as Google

http://uk.livejobs.recruitadvantage.com/job/job_details.cfm?id=15103&from=direct

Google also made a bit of a slip up and published their server settings recently (see below) leading to much debate about their meaning,  personally I wonder if –using_borg is a codename for the data provided by the hundreds of people involved in the not so secret eval ratings project. To quote Wikipedia:

The Borg or Borg Collective is a race of cybernetic organisms ... this biological and technological synthesis is carried out to achieve the self expressed goal of "perfection."

Google server dump:

"e_supplemental=150000 –pagerank_cutoff_decrease_per_round=100 –pagerank_cutoff_increase_per_round=500 –parents=12,13,14,15,16,17,18,19,20,21,22,23 –pass_country_to_leaves –phil_max_doc_activation=0.5 –port_base=32311 –production –rewrite_noncompositional_compounds –rpc_resolve_unreachable_servers –scale_prvec4_to_prvec –sections_to_retrieve=body+url+compactanchors –servlets=ascorer –supplemental_tier_section=body+url+compactanchors –threaded_logging –nouse_compressed_urls –use_domain_match –nouse_experimental_indyrank –use_experimental_spamscore –use_gwd –use_query_classifier –use_spamscore –using_borg”