Go for Europe. This is your second to last summer. There isn't much of a summer after 2nd year at all. I went to Europe this summmer and it was amazing, a dream come true. A bunch of people I talked to didn't like backpacking it. I ended up going w/a tour group because I sure didn't want to stay in hostiles or tent cities (yikes). A few people who were planning to back pack it said it was cheaper this way too. Anyways, they put you in 18-35 age group so most people are around their early 20's. There are a few, but try <a href="http://www.contiki.com." target="_blank">http://www.contiki.com.</a> They seem to be the best. Otherwise, plan wisely if you back pack it.
Europe is a must when you are young.
Peace,
wyldstyle2000