Reducing the time you run the shower for, to 5 minutes or less, reducing the heat and flow of the water or turning the water off, while lathering up, all reduce the energy used. Just one minute less every day means you save the cost of a half hour shower every month to your purse and the planet!
Getting fresh water pumped to our taps uses a significant amount of energy and chemicals. If we then heat it using a gas boiler, we use more energy and emit more greenhouse gases. By using only the water that we actually need, we can reduce our carbon footprint.