I listed a bunch of Asian Brassicas and herbs that I have available to swap or for postage. The "Asian Seed Swap" link in my sig block will jump there (a thread in Cubits).
For one-to-one trades, I also listed my two "Have" lists in my sig block, but they are somewhat messy at the moment.
I've started threads a few times in the ATP Group Buy / Classified forum, and the Trading forum, about a coop seed buy, or splitting large packets, but I agree: chirping crickets don't trade many seeds.