Your iPhone or Android device may be a very capable device, but you are not always have easy access to it. The Satechi Bluetooth Home Button is a compact device that lets you activate Siri or Google Voice search with a single press of a button, even when your phone is in your bag or pocket. Just attach the button to your steering wheel or keychain, and you are set.
This Bluetooth button has a range of up to 40 feet and a battery life of up to 2 years. The included mount lets you connect the BT Home Button to your steering wheel or onto bicycle handlebars. Sets you back $25 at this time.