Virtual worlds are highly immersive, engaging and popular computer mediated environments being explored by children and adults. Why then aren't more teachers using virtual worlds in the classroom with primary and secondary school students? Reasons often cited are the learning required to master the technology, low-end graphics cards, poor connectivity and the firewall. A solution to one of these barriers is to use a virtual world that can operate inside the firewall locally on school computers. The virtual world Sim-on-a-Stick provides a four region virtual world on a USB flash drive that is free and fully functional without accessing a network. Sim-on-a-Stick was used in a public primary school in regional Australia during term one 2012. This paper presents a case study outlining the implementation and integration of virtual worlds by a pre-service teacher, classroom teacher and her class. (Contains 4 figures and 2 tables.)