Other times you can find a job doing research in your field of student. Research jobs are fantastic. Not only will you build important contacts within the department, but the work you do outside the classroom can help reinforce the information you learn inside the classroom. This can be particularly important if you plan on pursuing a career in science. Science is a very academic-oriented profession, and research work, specifically laboratory research work, is a key prerequisite for career advancement, so start early.
Most schools have a variety of student clubs and organizations on campus.
Many of these groups are centered around fields of interest. Some of these organizations include Phi Beta Kappa, a student honor society, Toast Masters, a public speaking group, and the Order of the Engineer, an organization focused towards ethics and the engineering field. The requirements to becoming a club or group member will vary from club to club. The level of involvement will also vary. At the least, you would probably be expected to attend the regular meeting throughout the year.