I took a rickshaw from the airport to the Andheri train station after arriving from Abu Dhabi this morning. I then rode the train into the historic core of the city to Churchgate Station as the sun rose, unresistingly leaning out of the window holding to the top door frame most of the way. I walked the rest of the way to the Gate of India at the southern tip of the peninsula and found a single room for 600 Rs. (~$15) near the docks.
I return from a 4-hour undirected and labyrinthine walk through market after market progressing northward through the city. I walked fast but never felt at risk, but am still unable to take many pictures. Everything you have ever heard about Mumbai being chaotic should be regarded as true, albeit with a lot of harmony and tremendous excitement. The best moments of irony have come when this chaos is suddenly stepped up, when you come out of an acoustically-dampened indoor textile market and end up at the entrance of a packed train station, when you round a corner and end up on the meat-selling street of the Muslim quarter, where chickens are sold slaughtered on a board that sits on top of cages housing live ones. Life appears to just exist in a constant flow of material and service exchanges, it is strikingly timeless.
It was recommended to me that I eat mostly South Indian cuisine, for it will be easier on my stomach. Mixed bhajis on bread with pickle and chili sauce have been great so far.