The Internet of Things is one of the buzz phrases of the moment - the idea that there are a of a lot of devices around, from tiny sensors and RFID tags, through smartphones, GPS location-aware devices, laptops, and embedded systems. They are nearly all natively "online" to some extent, and most will have an Internet address of their own (even if the connections are not always super-high bandwidth, always-on, or reliable). So, they are becoming interconnected, either directly to one another across local networks, or indirectly via clouds. These devices typically have enough computing power to at least gather and transmit data, and some of them have enough to respond to requests to modify their behaviour. Many of these devices run Linux! So, with the lightweight nature of the systems involved, what about a lightweight but reliable messaging protocol that can help to connect them? Well, there's one available, it's called MQTT (MQ Telemetry Transport, see http://mqtt.org), and it's increasingly being adopted for some very cool projects like, for example, mosquitto (http://mosquitto.org/). This presentation will look at why lightweight reliable messaging is useful; what MQTT is and how to use it (including examples in a number of languages); and how it can be used in a variety of systems from home automation solutions and Arduino-based gadgets all the way through to city-wide transport systems, and even used to bridge up to messaging systems used by large enterprises.