Do you live in the same town as your relatives? I do not, and have a hard time remembering what they all look like. Years ago I made this lovely hanging board at a church function and decided to convert it into a "Family Picture Board". When relatives send us photos of themselves or their children I clip them up. My kids have loved getting to know grandparents, aunts, uncles, and cousins this way. If your family lives close this is also a fun way to remember fun family get-togethers and promote quality family relations.
My pictures are attached by a series of clothespins. You could use any variety of board to display your photos (i.e. magnet board, ribbon board...).