What are some travel programs that can give you great, cheap-ish deals?

I'm young and absolutely in love with traveling. But since it's so expensive, I've made it a goal to travel to another country every 2 years rather than every year. I'm paying for college and all on top of it, so other than study abroad, are there any other good ways to get relatively cheap international vacations?What are some travel programs that can give you great, cheap-ish deals?Personally, I have found Expedia to give the best deals on hotel/flight combos... However, any tours you want to take would be paid separately.