My suggested setup is as follows:
Donors mail in their seed to the bank. Seed should be dated and ID'd for species with donor's name on seed envelope.
Species are graded
1, easy growing, common, no dormancy or stratification needed.
2, dormancy or stratification needed, maybe special growing needs.
3, difficult to grow or very rare.
Seedbank Manager will keep an updated (more or less) inventory posted on the form on a regular (more or less) basis.
A forum member who wants seed will send an SASE to the Seedbank Manager. First they would PM the Seedbank Manager for his/her mailing address. (This should never be publicly posted.) They should specify what seed they're requesting. I was thinking of maybe a 2 species limit per month to allow everyone a fair shot at the seeds. Members might want to limit access to rare/difficult seed to experienced growers or less experienced growers who donate seed.
Members who receive seed should agree to Pay It Forward by donating seed from their plants in the future.
Seed donors should get priority when they request seed. People donating will make or break this Seedbank.
Someone stupid enough to volunteer to be Seedbank Manager is also a neccessity. This will be a thankless job with no benefits or privileges.
What do you think of this half baked idea? It's just an idea I've been thinking about for a while.