Hi Andy. I was in San Cristobal de las Casas , Chiapas, Mexico in the summer of 2012. I had just gotten there from Oaxaca, after an 11 hour bus trip with a Mexican company called ADO. Not wanting to walk around looking for a hotel with all my junk, I asked around and found out that in the Bus Terminal , ADO offers a service where they check-in and hold your baggage for a few pesos. After I found my hotel , I walked back to the ADO bus terminal, got all my stuff, and took a taxi back to the hotel for 25 Pesos- about $2 and change US. I have only seen this in Mexico.
That is a good service to offer, years ago in Airports, Bus Station, and other transport there were lockers. But since terrorist bombs have become trendy, most have stopped around the planet.