Pick any book on ancient India and you will find pages and pages on the origins  and decline of the Harappan civilization. You will also find details on the Aryan-Dravidian controversy. But when it comes to South India during the same period, there is nothing that exciting. There are no big cities or controversies. There is no Sarasvati or Rg Veda. South Indians were not among the first to domesticate crops and animals;this technology came from the North. On the whole the place looks jaw-droppingly jejune.
Now we know a lot more: on what developed indigenously and what was imported, on rituals  unique to the region and on how Neolithic globalization influenced the social structure.
First, not all crops were domesticated in Gujarat, Indus and Gangetic plains. Moong dal, urad dal, horse gram, browntop millet and hooked bristlegrass were domesticated in the south. Winter crops like wheat and barley were domesticated elsewhere and imported. Animal domestication too, it seems, was introduced from outside.
Second, cattle and cow dung had some significance. The zebu, for instance, is prominent in rock art and terracotta figurines. Also prominent were ash mounds, created by burning heaps of cow dung. Some of these ash mounds — unique to South India — were located outside the primary settlement and may have been used a place of gathering for some ritual and the burning of dung was symbolic. It probably had something to do with their belief system. In this gathering there was feasting and people exchanged beads, copper objects, cattle or the valuable Hiregudda axe. Maybe marriage alliances, which helped during times of need, were also made. You know what they say – marriages are made near the cow dung heap.
Finally, changes start affecting this idyllic community. Following the decline of the Harappan civilization, wheat and barley appear in the region. We also see crops from Africa and Indonesia, possibly through contact with seafaring traders. Remember that the Polynesians were doing sea cruises during this time and ships from Meluhha were reaching Mesopotamia. This trade, along the Indian Ocean rim, affected the Neolithic belief system and social structure.  Hilltop settlements were abandoned and people moved to the plains. There were burials with grave goods which look elitist. Hierarchies started forming.
References:

1. Boivin, Nicole, D. Q. Fuller, R. Korisettar, & M. Petraglia (2008) First farmers in South India: the role of internal processes and external influences in the emergence and transformation of south India’s earliest settled societies. Pragdhara 18: 179-200
2. K.A Nilakanta Sastri (the late), R.C. Champakalakshmi, and P.M. Rajan Gurukkal,The Illustrated History of South India, First Edition. (Oxford University Press, USA, 2009).
3. Moong Dal picture via Wikipedia