The suburbs of Homewood and Mountain Brook, immediately south of Red Mountain, have the most walkable retail strips in the Birmingham area. Homewood's 18th Street and Mountain Brook Village have independent clothing stores, antique dealers, bookshops, and specialty food shops within walking distance of each other.
Worth an afternoon browse if you're the type of traveler who prefers a real neighborhood to a mall. The Book Exchange in Homewood is a good regional bookshop. Mountain Brook Village has a pleasant European-village-scale layout that makes it one of the more pleasant places to simply walk around in the greater Birmingham area.