The roadtrip from Chennai to Pondicherry is a must go, especially through the East Coast Road(ECR). Literally as the name suggests, it's a drive along the coastline and you see beaches towards the right as you drive away to the destination. It a photographer's paradise! You can stop your car in between to get to the untouched beaches. This reminded me a lot of the roadtrip I had to Varkala, Kerala. It has similar topography with beach on one side while we drive.
From Pondicherry, it's just 11kms, approx 20 mins ride to Auroville, which is a peaceful community of people from all over the world! Best place for some yummy food and hippy clothes shopping at dirt cheap rates.
If you have time, do a prior booking for a tour of mantrimandir, the most ornate exquisite meditation room I had ever been to!