Activities
I have been actively involved in various social activities since my school days, and especially have a keen interest in primary education. When in IIT Bombay, I started a group called 'Manthan', in collaboration with a NGO (/non-profit) called Vidya. We used to teach underprivileged children on the IIT campus.
Activities
VOICE
I was also a volunteer teacher for 'VOICE', which helps street children in Mumbai achieve a better future. For a long time, Voice worked with minimal infrastructure on railway platforms to reach out to these children. On recent visits to India, it was heartening for me to see that Voice now has its own schools and a rehabilitation center, and has made a huge difference in the lives of many street children. Definitely check out their website.
Udai
In UCSD, I joined in with a bunch of Indian graduate students to form an organization called Udai. Our aim is to promote awareness of social issues and contribute to their alleviation, with projects in fields like education, health, technology, etc. Over the years, Udai has done a lot of good work and has collaborated with many NGOs on specific projects. Please go to the Udai website for more details.

Also, check out the following websites of organizations Udai has worked with:

Jagruthi

Digital Study Hall

Mozda

NGO Post
Nitin and Parul, two of my friends from Udai, have recently started NGO Post, a forum for sharing stories and solutions about social issues.
The NGO Post latest news widget: