Some of the credit for this must go to the Women in Business Network, which has helped to encourage women in the region to develop their own small businesses. The network was set up in January 2005 by Jan Ibbot, to help female-led small businesses in the UK conduct more effective marketing on a limited budget. Their website says that "WIBN is a fast growing organisation dedicated to business women and business owners. With plans to grow nationally during 2008-2009, our growth will enable us to offer both business support and encouragement to women in business around the UK." Interestingly, they're expanding the network through franchising.
You don't need to be female or live in Dacorum however, to benefit from networking. Most towns have at least one informal business group (aside from Rotaract, Round Table etc) that is dedicated to fostering and encouraging small business growth.