Physical shopping carts can have product detection systems and associate physical shopping carts with mobile computing devices (e.g., smartphones, tablet computing devices, smart watches, wearable computing devices). For example, physical shopping carts can be equipped with one or more product detection systems (e.g., scanners, sensors, cameras) that can electronically tally products that are placed in physical shopping carts. Mobile computing devices can be associated with and mounted on the physical shopping carts to provide a variety of enhanced shopping cart features not possible with conventional physical shopping carts, such as electronically tracking the contents of a shopping cart, checking-out from the mobile computing device (instead of at conventional check-out areas, such as point of sale terminals), and others.