Yep, thats it, the blue one, but I dont know why i recalled there being four divots to press on the top, maybe there were four divots on another brand and I got confused (was there a spring valley flavoured mineral water at some stage?) anyway yep looking at that now, thats the one - pop top. I could never see how the pop was supposed to work - I always assumed, you pushed the small one and the other was somehow supposed to open due to pressure or something, but of course it doesnt, and you have to squeeze your finger past the edge of the hole to open it properly. Dunno why I've always thought that, must have been an idea I got when I was a kid and it never went away!

Another image I have from the 70s is ring pull chains - people would collect a heap of ring pulls and make a chain by bending/rolling the tang of the first ring pull around the ring of the next and so on. One Christmas, our neighbours had one that went right around the living room and onto the tree. I was pretty young, I just assumed the much much older teenage brother in that house who had made it had drunk a heap of soft drink that year! I remember he had an electric guitar, the first one I ever saw, on reflection, the ring pulls probably didnt all come from soft drink!