Get Your Students Hired
Groups working together on a project actually puts the students in the role of instructor in many ways, the individuals who have more experience/knowledge can help the ones who are a little less experienced and therefore everyone benefits. I've also noticed that having a student help another student often makes it less intimidating than if I as instructor were to provide feedback/guidance. I monitor the interactions so that incorrect info doesn't get out there, but for the most part - having groups work together is very beneficial for faciliating learning.