Ancestry.com’s World Archives Project will have volunteers indexing digitized records using an online tool. Ancestry.com will publish the index free; the record images will become part of the site’s subscription services.
FamilySearch’s volunteer indexing program is producing both indexes and record images that will be free online, though in some cases, you’ll need to view digitized records at one of FamilySearch’s Family History Centers. One such example is the US census partnership with none other than Ancestry.com.
From the November 2008 Family Tree Magazine