My question covers both Site-Wide link + Google PR if I am opting for a site-wide link with any other domain.

1. does PR from each pages where text link is placed adds to my target domain value ?

2. does links from each and every page from domain where link is placed gets new backlings to my domain ?

Practically in case of yahoo = yes
case of google = no
case of MSN = dont know.

More feedbacks please.