use
www.hardlinks.org to backlink these sites you mentioned...
"then we have about 10 domains that are just copies of the front page of one of the main sites, the domain is the seo keyphrase we are targetting and the rest of the page is SEO'ed for such. and getting maybe 10-20 hits a week total from that"
use several different keywords per domain
Have a great weekend,
~Ray