Haiku (a fast, simple to use operatin system successor of BeOS) is trying to atract more funding for sponsoring more developers to work full time on the project.
They've recently added a trio of new options for helping them succeed.
First they've partnered with GoodSearch (a custom search engine based on yahoo) so that they can earn part of the money generated by the ads showed on the search results. You can find further details on the official announcement.
Second they've created an official Flattr page (social donation system tailored more towards small subscriptions). You can find further details on the official announcement.
Third but not last, they've now started to accept Bitcoin donations. You can find further details on the official announcement.