On our web site, we have an area called "The Exchange". In this area, you can post items you have for sale, or your lost and found items. By default, items will stay out in the exchange area for 2 weeks, but you can extend the time or delete the item at any time during the 2 weeks.
It may be best to start your description with the key word for what you are trying to sell - like SKATES or HELMET or GOALIE LEG PADS, or LOST or FOUND. We're open to suggestions... Hopefully this feature will be helpful, as I've already heard from one family who is missing a pair of gloves, and should be posting that in the exchange soon.