Volunteer in the USA (Summer Camp)?

Hi. I'm just wondering what my chances are doing voluntary work in the USA next year. I am up for any kinda outdoor voluntary work whether that would be a volunteer at a Summer Camp or doing something else.

I don't mind even if its somewhere else like Australia, South Africa or some place else just as long as its not in the UK, preferably I'd like it to be in the USA.

I have no convictions, I've been to the US a few times for vacations in the past and would love to go back again.

I am 28 years of age and I'm not a student and I have never been to university... would that affect my chances or am I just dreaming and have no chance?

I have looked at a few websites regarding this but cant seem to find much info on the subject.

Any info such as links to websites would be much appreciated.

I'll give 10 points for a best answer even if it is all doom & gloom.

Thanks.