Two very popular New Year's resolutions: get in shape and try something new.  Why not kill both those birds (and also impress a lot of people) with a visit to one of San Francisco's climbing gyms.  There's old-timer Mission Cliffs (2295 Harrison Street) and new-comer Planet Granite just off of Crissy Field (which boasts some seriously impressive views of the Bay).  Both gyms offer lessons,  routes for beginning and advanced climbers and extensive bouldering terrain for those who don't want to tie in (e.g. hang from ropes).  So next time you find yourself slugging towards the treadmill or an overcrowded yoga class, get your belay on instead.