GSL is a labwide year-long event at CSAIL that occurs every Friday during the semester. A group of three to five people cook lunch for everyone else, and CSAIL pays the bill ($265 max). You only have to cook once to be invited to free lunch every Friday for the whole year. Also, cooking and eating is a great way to get to know your labmates in an environment that doesn't involve code or proofs!
Anyone is welcome to participate in GSL - undergrads, grads, faculty, and staff. Pick choose a date on the sign-up sheet, or e-mail Prasant (prasant at csail) for additional info.