Two separate readers have recently contacted me, lamenting that their usual clothing donation drop boxes have disappeared. (Specifically, the box at Grand and Fulton, and the box on Myrtle near Tamboril.) Where else can one drop a donation? Personally, I bring stuff to the Goodwill on Fulton near Franklin. They take clothing, books, appliances, etc, and they also provide you with a receipt - key for tax season!
Other options include the Salvation Army on Quincy between Downing and Classon (near Broken Angel), and the library on Washington between Greene and Gates - I noticed a clothing donation box at the circulation desk a few days ago (I think they're collecting clothing through December).
Hope that helps!