Kent parish register extract index - ancestry
 

This is one that was indexed by the World Archives Project Volunteers, so it should be free to search for everyone (though you will only see the images if you have a sub or key for WAP):

http://search.ancestry.co.uk/search/db.aspx?dbid=1901

I'm not sure what the coverage is like but I got the impression when indexing it that only certain families were included. Worth a look if you have ancestors from Kent though, just in case.

Also it looks as though the Kent extracted wills index is going online soon too as there is a link to it (which doesn't work at the moment) on the PR index page.

Well, the PR index certainly has some of my ancestors listed.