It’s Friday, but with all the saving for Christmas presents and whatnot, you’re looking for the cheapest method of fun before the holidays. You’d probably even be up for a free beer, even if a slight competition were involved. You love a challenge. From 7pm on tonight, at 5th St. Ribs n Blues (86 5th St. NW, Midtown, 404.249.8808), the PBR will be free-flowing. Of course there’s a catch: The beer’s only free until one of the particpants of the special either leaves the restaraunts or goes to the bathroom. Laugh if you must, but where else are you going to score free brewskies tonight?