Ask HN: Please post information related to Non-Traditional Payment Models

I'm interested in hearing about innovative/alternative payment schemes suitable for digital goods. I know there has been a lot of research aimed at alternative models for the music industry. Here are some links I've found:

Ransom Model (some interesting links at the bottom)

--- http://en.wikipedia.org/wiki/Threshold_pledge_system

Assurance Contract (related)

--- http://en.wikipedia.org/wiki/Assurance_contract

Article providing overview of some services that approach the music industry problem in different ways

--- http://www.last100.com/2007/10/11/music-industry-five-alternative-business-models/

Interested in reading what you all post!