E-learning technologies have matured to a point where distance learning classes are commonly offered from many leading Universities around the world. A major challenge in such distributed classrooms is the formation of virtual communities among the participating students, enhancing the overall learning experience. Shared virtual laboratories offer the possibility of forming such virtual communities as students form lab teams to run the same interactive simulation and in the course of such experiments learn to interact and understand each other better. We have designed and implemented a Virtual Scientific Experiment architectural framework on top of a Grid infrastructure for running interactive virtual laboratory experiments for such distributed student communities with visualization capabilities. The architecture is based on Web Services standard protocols such as WSDL and WS-Notification as implemented in the WSRF specification. For the first concrete instantiation of this architecture, we ported a stand-alone Wireless Sensor Network simulator written in Java in our Grid-based architecture and extended it to allow for initial collaborative parameter setup and on-the-fly visualization of the simulation execution and interaction with it, a capability not present in the original simulator. We report on results from running such simulations on a local Grid infrastructure. System evaluation results from a distributed pool of students show the added value of our system in enhancing distance-learning programs and Virtual Classes with extensible collaborative and interactive Virtual Laboratories sessions.