Free Africa Volunteer Programs

I would like to do volunteer work abroad?
I lost my job about a month ago due to the credit crunch and I have tried to find a new job but the job markets so hard at the moment. I thought rather than sitting around being bored and doing nothing I would like to do something good with my time like volunteering in a lesser privileged country preferably in an orphanage in africa or asia for a few months or something. The only thing is all the volunteer projects I can find are so expensive to actually go they seem to cost about £800 and that's before you even have your flights and visa.
Are there any free volunteer programmes or at least very cheap ones? as I said i'm unemployed and i didn't get much of a redundancy package as i'm only 21 and had only been working there for 3 years so I can't afford to go on any of these programmes.
Non-profit organizations want to use the money they have to benefit those they have collected the donations for rather than paying for a volunteer. So yes, it is going to cost you something to do volunteer work abroad. Even the Peace Corps, which does pay a salary to it's volunteers, expects you to pay for your travel and the salary they pay is based on covering living expenses in the area where you are working.
Some volunteer abroad organizations do try to provide volunteers with a low cost experience and I have included some links for you to check.
Volunteer HQ appears to be fairly affordable.
GLA Africa - Ghana: Volunteer Abroad Program for High School Students