Had a quick 2-day visit to Pondicherry.
We the beach-deprived people from Bangalore definitely need to drive down once in a while (about 6-7 hours) to enjoy the beautiful beaches. The promenade is maintained beautifully, and the sea crashing onto the rocks is such a beautiful sight! There are other beaches too if you go along the ECR road, which connects Pondicherry to Chennai. The beaches are quite steep in some places and is not safe to go with little kids.
But there is a really flat beach near Chummanbar resorts. They call it the water sports complex, but there are very few boats there. From 60 bucks per person, they would take you on a normal boring boat to an island about 10 minutes away. That island has a very nice flattish beach, which kids would love.
Did not get time to visit the French colony and Auroville. Should go there next time:)