Western Australia's Days of Change program was launched this month. The program works by "providing a forum in which people can make public commitments to reduce their footprint, and then supporting them in making the changes to fulfil their commitments."
This is a great way to make a first step in shifting towards a healthier and more sustainable lifestyle. However, I'd encourage you to also think beyond individual actions. As well as pledging to catch public transport or cycle more often, for example, you could also pledge to write a letter to your government representative asking for better cycle paths in your area. Individual action helps, but we also need to work to build better communities and put pressure on government.