A vending machine system for exchanging CO.sub.2 gas cylinders, the system including a controller in communication with a user interface, a payment system and an array of bin assemblies, wherein each one of the bin assemblies is shaped to at least partially receive an end of a CO.sub.2 gas cylinder and includes a locking system for releasably securing therein a CO.sub.2 gas cylinder, said system for performing the steps of (a) receiving user input through the user interface; and (b) if the user input represents a desire to exchange a CO.sub.2 gas cylinder, then the system performs the steps of (i) receiving payment from the user through the payment system for a replacement CO.sub.2 gas cylinder; (ii) receiving a CO.sub.2 gas cylinder in a first one of said bin assemblies; and (iii) the locking system releasing a full CO.sub.2 gas cylinder located in a second one of said bin assemblies for collection by the user.

Various embodiments of kiosks for purchasing mobile phones and other mobile electronic devices from users are disclosed herein. In some embodiments, the kiosks include an apparatus to position an electrical connector for connection to a mobile device. This apparatus enables the kiosk to connect to the mobile device to electrically inspect the mobile device, and the associated electrical connectors and cables are not subjected to repeated pulling and other rough handling that can lead to premature wear and tear. Accordingly, use of connector carriers configured in accordance with the present technology can lead to longer connector/cable service life, reduced maintenance, and greater kiosk up-time. In some embodiments, the apparatus can include a camshaft having one or more cam lobes positioned to act against one or more cam followers, e.g., carrying one or more electrical connectors.