go study abroad. I did it, and it was the greatest experience of my life. plus, i figure it'll give me something to talk about that's a bit different than research.
Or, if you'd rather go more traditional, you can do that to. Just remember, if you don't want to do research, don't. You can volunteer at a hospital, EMS, hospice, public clinics, the possibilities are endless really. If you want to do research, talk to some of your professors and see if htey need anybody for the summer, or if they know of anyone who does. that's how it's done in my school anyway, or they'll actually offer it to you if they really need people, which happened to me last year, but i turned it down to study abroad.