There are over a billion PCs in the world. Most of these PCs can be found in citizens' homes and, to a lesser extent, in universities. Most of these computers remain idle most of the time. About 1 million of them are active in supporting science in a volunteer computing grid and use their idle time to run scientific applications.The potential growth of this computing capacity is enormous. Many Desktop Grids have therefore decided to found the International Desktop Grid Federation (IDGF) to help each other improving their e-Infrastructures.The IDGF-Support Project will give the IDGF a boost in two important areas. Firstly it will help considerably with increasing the number of citizens that donate computing time to e-Science.It will do so by targeted communication activities and settin-up a network of "ambassadors". Secondly it will help universities' e-infrastructures to include otherwise idle PCs from their class rooms and offices. In addition IDGF-SP will collect and analyse data that will help deploying idle PCs in an effective and energy efficient way. It has been shown that Desktop Grids can contribute to Green IT if used in the correct way. IDGF-SP will collect data to underpin and advocate best practices.As a result of IDGF-SP, the number of citizen volunteers donating computing to e-Science will increase significantly. By employing unused PCs in private Desktop Grid, universities and other research organisations, will save on their costs on providing computer capacity for their scientists. IDGF-SP will help strengthening the co-operation amongst Desktop Grid e-Infrastructure operators. IDGF-SP will encourage and help IDGF Desktop Grid providers to integrate their infrastructures into the main e-Science environment. The existance of an lively active IDGF community assures the swift take-up of the IDGF-SP project results.