Go to
www.ifmsa.org, click on "exchanges for medical students," then "research exchanges," and then search the database by country, subject, etc. There are hundreds of labs/projects listed, both clinical and basic science.
I did research in Germany the summer following my first year. Most of the opportunities on the website will involve you paying for your trip, but it is usually VERY cheap. I actually found an awesome professor who offered to give me a little $$$... enough to pay for housing and have a little left over. Since I planned on going to Europe for the summer anyways, it was great just to have a basically free place to stay.
For some reason, U.S. students aren't aware of this organization, thousands of medical students from other countries do these exchanges. When I was in Germany, there were also 2 students from Taiwan, 1 from Peru, 1 from Spain, 1 from Lithuania, and 1 from Austria... and that is just in the 1 city I was staying in.
Anyways, check it out and if you have any questions let me know.