There are businesses and then there are businesses. Some of them are 'social enterprises' which the Social Enterprise Coalition describes as "dynamic businesses with a social purpose working all around the UK and internationally to deliver lasting social and environmental change." (Or as a friend put it: "Social enterprises are primarily intended to change the world not the bank balance of the entrepreneur."). Their web site puts the number of social enterprises in the tens of thousands and a combined turnover in the billions.
Among examples are Cafedirect, The Big Issue, The Co-operative Group, Welsh Water (Glas Cymru), the Eden Project and Jamie Oliver's Fifteen, but there are lots of others around the UK in pretty much every sector you can imagine (including football supporters' trusts). On their web site you'll find lots more information plus plenty of case studies. If you're in Scotland, you should also try the Scottish Social Enterprise Coalition and there are also numerous regional groupings such as the Social Enterprise East of England with their own real and virtual meetings, magazines and shared local knowledge.