The Internet of Things (IoT) integrates the physical world with the existing Internet, and is rapidly gaining popularity, thanks to the increased adoption of smart phones and sensing devices. One of the important challenges in this domain is to enable domain experts to easily specify applications for the IoT. As a first step towards developing a suitable programming abstraction, in this paper we present a domain model for applications in the Internet of Things, based on a survey of recently proposed IoT applications from the real world that represent a wide class of behaviors found in IoT use cases.