I've been involved in the bloggers for #ShareNiger project for a couple of years now, and it is a worthwhile thing to do. We are sponsoring a number of children in Niger through WorldVision.
The request was a commitment to share sponsorship of the children, so that we are committed to £6 a month each. Each child consequently has four of us sponsoring them.
Due to various problems and hiccups, some of the supporters have had to drop out and there are some spaces. We are hoping that more people [and not necessarily bloggers - the children don't care who sponsors them really!] will come forward to help. If that could be you, please send me a message through the comments.
Some people set up a direct debit but I just send an annual cheque to the organiser. She then sends us out copies of the updates on our respective children each time she gets them. Click on the button in the sidebar to the original post on my friend's blog to learn more about the project.