Does anyone know of volunteer abroad services that are not overly expensive?

I am looking to leave the country (i currently live in New York, United States)

ANYWAY i have been researching places to volunteer abroad, preferably somewhere in Africa.

I CANNOT however find a program that is less than1000s of dollars just to volunteer for a week or so...

i have become quite frustrated b/c none of this even includes the plane ticket. i dont have that much money, but its SO expensive just to volunteer. i understand these organizations need money to help the children with what they need, but these programs make it so hard for working class people to take part in something that may be important to them.

I am high school senior and right after graduation (June 09' and ill be 18 by then) i want to leave to volunteer in an orphanage.

is there any programs that are reasonable, something i can afford? or are there any programs that provide scholarships or financial aid?
i know there probably isnt a lot, but i am sure there are some.
I would ideally like to work in an orphanage in Africa, but i open to other continents...i guess whatever provides me with an ideal opportunity. But i most deff. want to work in an orphanage.
THANKS A MILLION!!!

rotary is pretty expensive but might work with you.