This paper presents an experimental setup based on the LEGO Mindstorms technology, suitable for the validation of cooperative control strategies for multiple vehicle systems. Despite its low cost, the proposed setup features good scalability and is versatile enough to be adopted for testing different solutions to a number of crucial problems arising in multi-agent systems, like formation control, motion coordination, coverage problems, etc. At the same time, it represents a challenging testbed, presenting several issues that have to be faced in a real-world scenario, such as communication constraints, control quantization, noisy measurements. As an application, the experimental validation of a recently proposed decentralized control law is presented, for the collective circular motion of a team of nonholonomic vehicles about a virtual reference beacon.