Is there a keyboard shortcut in Firefox to permit a site to open a popup
(e.g., Alt-click on link)? If not, is there an extension to add this
function? I'd like to be able to open a popup window when desired
without changing the permissions for the host site and without waiting
until after I click the link, get the popup toolbar warning, and click
through the Options pull-down.

For example, I just went to a MLB baseball site through mlb.com (pick
any team currently in a game) and clicked the Gameday link, which would
then open a streaming gamecast (not video). I don't want to add all of
the teams to my white list, but I do occasionally check a non-favored
team. Also, since I did add my favorite team's site to my white list so
that the Gameday link would work, I get popup ads from the parent site, too.