Peace Corp kinda things?

[JaneYoung]

'No' is tough to hear especially when one has the best of intentions.
Respect it.

Many times it is as difficult for the parents to say as it is for the young person to hear.

.02
Jane

[KenWittlief]

The only personal experience Ive had with the Peace Corps is that I worked with a co-op student who had been involved (was overseas, Africa I believe).

She said she hated it, and literally counted the days till she could come back home.

(One of the worst things about being human is when you get older, and you find out your parents were right about so many things!).

[Kyle]

Why don't you volunteer with your local Fire Dept.? You don't have to fight fire there are many many many things to do in your community as a member, you can get training and help teach fire safe habits, CPR/aed and first aid training to people in your school/ community.
I love being a Firefighter I hope to do it one day as a full time paid dept. I am an instructor for the Red Cross and American Heart Association. I have taught many people how to do proper CPR, it is really surprising how many people don't know how to do it, and just think they can.
Other things you can do in Fire Dept, is to work with getting more members, fund raising and community events.
Its lots of fun and you make some great friends.

[Eugenia Gabrielov]

First and foremost, I want to applaud you for your ambition. Very few people do this kind of thing...and let me point out a couple reasons that might be issues with your parents.

1) Are you under 18, or over 18? Remember, as a minor, you have much less ability to deal with certain situations alone. For example, there is a lot of liability. Your parents may just be concerned that you won't be able to handle yourself in a dangerous situation. Most projects go by without a glitch, but there is always that issue.

2) Have you travelled alone? Really, alone? I don't mean on a school trip for robotics, or to the next town over, I mean international travel. I thought I knew everything about being on my own when I went to Spain to study abroad this summer without Mom and Dad to take care of the technical stuff for me - boy, was I wrong!!! I had a VERY rewarding experience, but I also came to understand how much difference there is between travelling on your own and studying or volunteering, and being a tourist.

3) Are you already responsible? I don't want to pass judgment on your character - I'm sure you're great if you're even considering this - but you may need to really prove yourself first.

So let me present a couple solutions, and expand upon what other people have mentioned:

Step 1: You need to prove you can be by yourself and handle a service project.
Find anything where you can volunteer. Do some work. Be on a schedule. Show your parents that you won't just slack when you actually have to work. Work outside. Work hard. I don't know your skillsets, but you do - take advantage of them.

Step 2: Choose a volunteer opportunity that will apply to an international project
Sure, cleaning pet cages at the Humane Society is a great volunteer effort. But will it really help you nurse natural disaster victims back to health? Will it help you construct a house for a family in need? Will it help you build a well, or repair a school? Not entirely. Choose volunteer opportunities that will apply to not only your volunteering goal, but also to your future. A few examples...

Let me call out some examples:
Imad mentioned he volunteered a LOT at Smithsonian. He's also going into engineering. Smithsonian is sciency - a good resource for connections, a good opportunity.
I am going into Medicine as a career. I have volunteered for two years as a breast cancer researcher and lab techie at a Breast Cancer lab in Purdue. What I'm learning now applies a LOT to what I'll be doing in the future.

You don't necessarily need to connect your volunteer opportunities, but having those connections is great because you have a natural follow-through of activities. As soon as you prove to your parents you can take a step, then they'll be much more likely to let you take a leap. Good luck