At GeoWoodstock this year, everyone who purchased an event geocoin also received a free proxy coin from GXProxy.com. The idea is that you keep your collectible event coin safe at home, and send out the proxy coin in its place. If the proxy gets lost or stolen, you can purchase a low-cost replacement and release it to resume its mission. Whether you buy a replacement or not, your original geocoin stays safe with your personal collection. This idea works for any geocoin that you have designed and would prefer to send out low-cost copies to share with others, rather than risking the loss of an original.
For an even lower price, you can purchase a "Ready2Go GXProxy coin" in one of their standard designs, and have the tracking number from any geocoin you own stamped on it. These single-color 1.75" x 3mm anodized aluminum proxies are durable and come in a variety of colors. See GXProxy.com for more details.