"Mashup" is a new technology term used to describe a web application that combines data or technology from several different sources. You can apply this concept in your classroom by having students create their own mashup maps. Google Maps provides you with the simple tools, map databases, and online help you'll need to quickly master this web-based application. All you'll need is a collection of student data that you'd like to translate into a high-tech, interactive, multimedia map. This article describes how the authors used the data collected about local trees to create a mashup map. (Contains 5 figures.)