You should either be rummaging through your closets for relics to sell or collecting pocket change for a little something to spend. The first-ever unofficially official Fan Flea Market — a community-wide yard and sidewalk sale — is happening this weekend, Saturday, April 25, from 10 a.m. to 3 p.m. We say “unofficially officially” because this surely isn’t the first collaborative call for yard sales in the neighborhood, but there is one factor that makes the Fan Flea Market stand out. Organizers created an online map to track participating residents. The list currently features 50+ planned yard sales spanning from South Harrison Street to South Arthur Ashe Boulevard. Bonus: If you click on a pin, you might find a note about what that particular residence is selling…