So used to be the saying... that a link from the Yahoo directory gave a significant boost in rankings, especially if the right keywords were present in the link. But that was back when DMOZ was also quite important in Google's vision. I don't know if Yahoo plays much of a role these days.

Every link counts, but a link on a page with tens of links... I doubt it's value is that high. Also, it depends on the PR of the page your site ends up on.