Ideas for a reusable smart contract component - Agoric/cross-chain-hackathon GitHub Wiki
DAOs
Negotiation
Loans
Arbitration
Assurance Contract
Conditional Cheque (better known as Letter of credit for some reason)
Insurance bond
Payment cascade. (First-tier gets paid first, if any left then the second tier and so on)
Grant matcher („I will donate 20 buckazoids to Amnesty Interstellar but only if you donate equally to them too“)
n-of-k wallet/authorization/escrow
Art-Asset Assurance contract (example: an author of an ongoing serialized story has already written a chapter but wants 200 zorkmids for it to be accessible to all, yet the payers want to be sure they get the chapter)