By default Photoshop allows you to switch between tools of a specific group by holding down the SHIFT key and pressing the letter that represents the tool. So for example, the Dodge, Burn and Sponge tools can be activated by pressing the letter ‘O’ on the keyboard, and then to move between the tools, use the SHIFT +O combination. So if the letter ‘O’ activates the Dodge Tool then pressing SHIFT + O will activate the Burn Tool, and pressing it again will activate the Sponge Tool, you get the idea.
