Impetus provides strategic funding and expertise to charities and social enterprises that have a significant impact on the lives of a substantial number of economically disadvantaged people. They give support to their chosen organisations over a defined period of time (usually three to five years) with the aim of enabling the organisation to scale-up. http://www.impetus.org.uk

DFID Civil Society Challenge Fund
The Department for International Development's Civil Society Challenge Fund is aimed at UK-based not-for-profit organisations working to provide lasting benefits to poor communities and under-represented people in the developing world.
http://www.dfid.gov.uk/funding

Free pack of six guides for small and medium sized organisations, covering fundraising, trading, contracting and much more. From NCVO's Sustainable Funding Project and the Finance Hub.

O2's It's Your Community awards provide up to £1,000 to local groups and individuals for anything that can be shown to benefit their community. http://www.itsyourcommunity.co.uk