I haven't been on this site for a while but yes I do remember the chameleons at school and putting them into water to see if they could swim - poor things!
I remember Msasani beach (through sisal plantations, wasn't it) and also going over to Bagamoyo by ferry to the beaches there (I think it was Bagamoyo over the ferry). I remember the markets but I was also in Dar as an adult so have memories of shopping in the markets and of buying fish from the quay as it came off the boats. I didn't leave Dar until 1972 but it all seems such a long time ago and I've never thought about it much since - only the odd incident. I wish my memory was better!