The way my other group did it was a thread was left up for a couple of weeks so that as many people could participate as possible. Say there are 20 participants, each person would buy a single bead for each of the other 19 participants. A member volunteers to receive all the beads in the mail and then mails out beads to the other participants. That member would PM her address to the other participants who would then mail her their beads, as well a a large self addressed stamped envelope so that she can place the beads sent by other members and mail it back to each member. In this scenario of 20 participants, she would send each participant 19 beads in the SASE they provided. We would decide a date that the beads need to be received by. Once we all receive our beads, we will string them onto a birthing necklace and wear them while giving birth.
I'm hoping some mamas would like to participate because this was such a positive experience for me my last pregnancy. :-)