On missions trips, I feel that their main role is to help missionaries to meet a task they would otherwise be unable to, due either to a lack of necessary skills or manpower. Examples of this would be disaster relief, healthcare trips, church building, or surveying. Conversely, what I see happening often, especially with youth trips, is that there is not much of a need that is met. Yes, there is exposure and growth from the team's side as they see and experience the great commission and there is community built between the local church and the sending church, but there is often little true progress or achievement and it can end up draining for the receiving missionaries.
A good example of a large team of students being put to good work is from about 6 years ago, when a professor from Southeastern, took some students to do evangelism work. As part of the trip, they did some surveying, some work with local churches, and they cleared a field. This field, you see, belonged to a school some of my parents' colleagues were trying to start a program with. Normally, it would have taken a month or more to clear the rocks from it and make it usable, but these students did it in a day. As a result, the school allowed the missionaries to run their after school program.
So, as far as youth trips and other trips go, they have good use and purpose, but they need to be done well and not foster a poor first world - third world perception, which is my second point.
My beef with the Children of the World choir (and other projects like it) is that is exploits the third world and presents a false representation of these nations and cultures. Every time I see them perform, I am reminded of a song by Johnny Clegg, titled "Third World Child," in which the chorus goes:
"Learn to speak a little bit of English | Don't be scared of the suit and tie | Learn to walk in the dreams of the foreigners | I am a third world child."
I know that many of these charity projects do good work. CotW provides good education and quality of life for these kids and brings awareness of people in other countries. The negative is the way that awareness is presented and processed. To me, it looks like the image presented is that they've taken these kids from a poor environment, clothed them, taught them, and are now showing them off. There's no celebration of the individual cultures; it's all homogenised into the American Church experience. The image portrayed, then, is that we, the first world, need to go into the "dark," "lost" third world and give them what they need to be like us, that we need to intervene. What is needed isn't intervention, but investment. We need to send skilled, trained individuals from the first world to train those in the third world in necessary, marketable skills: digging well, building houses, farming, pastoring, etc. In doing so, we encourage self-reliance and foster growth of the local GDP, enabling it to develop, while not forcing an American perspective or ideal overtop the ideals, flavors and actual needs of the particular culture.
A classic example is Haiti - when the disaster struck, we responded correctly, providing needs. However, we've stayed way too long. It's been a number of years since the earthquake and we're still going and giving supplies. Why? Well, we see that everyone's still poor and needy, but the issue is that they're still poor and needy because there's no incentive to change. After all, the US is always sending people with stuff they need.
So, in a nutshell, my biggest grievance is the objectification of the third world and the reaction thereunto. Second is the manner in which youth missions trips, while beneficial to the team members, often do not benefit long-term either the missionaries or locals.