i get them from the ocean, but i guess that isn't an option for everybody. most lfs will sell them to you before they give them away, unless you've got a buddy that works there. however, try looking in one of those fabric and craft supply stores that your grandma always hangs out in. i was in one such place with my girlfriend once and found a decent selection of shells that i guess they sell for people to glue onto hats or something, (???), and they were so nice i actually bought a bag just to spice it up in my tank.