Science and Public Policy Institute
(It should not be confused with the earlier pro-public-health think tank of the same name.)
The SPPI states it is "a nonprofit institute of research and education dedicated to sound public policy based on sound science. Free from affiliation to any corporation or political party." It does not reveal its funding sources; however, it shares a building and personnel with the Centre for Science and Public Policy, a project of Frontiers of Freedom, which gets its money from the oil industry (a million from ExxonMobil for a start).
SPPI's greatest hits include a report in which they claim that sea levels have not risen, their evidence being a graph showing sea level rise, but tilted such that the long-term trend is flat. Yes, really. 
Also among its personnel listed are Craig Idso of the Center for the Study of Carbon Dioxide and Global Change and Willie Soon.