My wife and I volunteered with SPPD for two months in July and August 2011. My wife taught English and I gave computer literacy lessons.
It was great! The children here are very friendly. They are respectful for teachers and eager to learn. Even though they had had very limited experience with computers (and even didn't know what Internet is) they were able to learn new things quickly. For example, besides typing and drawing I managed to teach them some vector graphics in Inkscape, data analysis in Gnumeric, and even Linux commands. They hungrily learn whatever you teach them, and enjoy it even if they don't always understand what those things are needed for. It was fantastic to see their progress.
The friendly staff of SPPD organised our stay very well. The place where we stayed is nice and clean. We didn't expect such a comfortable accommodation from rural South India. The building is eco-friendly, so it stays cool even during hot weather. There are many trees around that provide shade. The food is tasty. It is simple but healthy.
More than anything else, we enjoyed being with the children. Despite their difficult and often tragic circumstances, their hearts are so full of love, that they are happy to share with you.