The depot's Web site bills it as "every teacher's first stop and every artist's second home." But it has a third, very Earth-friendly mission as well: Keeping clutter out of the landfill and turning it into something useful. Need to painlessly get rid of (or magically find) an extraordinary number of empty film canisters? How about a zillion rubber bands? Carpet samples? Glass bottles? Bowling trophies? Have no fear. For nearly three decades, this outlet has effortlessly matched those looking to dispose of household odds and ends with the very people who need them often schoolteachers seeking supplies for art or science projects, or creative types looking for funky materials, not to mention inspiration. Even if you go without a shopping list, it's always a pleasure to sift through the stacks and discover an unexpected treasure. The depot is moving to its new, expanded digs at 4695 Telegraph Avenue on May 19. To ease the transition, it won't be accepting any new donations until then.