Whereas coffee is the daily morning beverage for most of the world, in Argentina it's yerba mate, except change "morning" to "all the time", and "beverage" to "religion".
It's an herbal tea (or infusion for our nonexistent British readers out there) with its own unique and traditional delivery method containing two parts: a hollowed out gourd, called the mate, and a silver straw with small slits or holes in the bottom end, called the bombilla. Both can be made extremely ornately, often decorated with silver or other precious metals, and we saw many for sale, from the cheap ones from street vendors, to the heavily ornamented being sold by the country's poshest jewelry and trinket shops.
To drink the infusion, you put the straw into the gourd, fill the gourd around it with the dry leaves, then pour hot water over the leaves. After waiting a minute or two for the tea to steep, you drink through the straw, with the holes keeping (most of) the tea out of your mouth. Because the gourds are fairly small, and the tea gets very strong before long, the traditional way to drink mate is to also carry a thermos, and refill the gourd whenever it gets low.
Mate is slightly caffeinated, but contains less than tea or coffee, and there's evidence showing it has a positive effect on muscle tissue, heart disease, obesity, cholesterol, and even cancer, but check the wiki for the full details and the many s
Everywhere we went in Argentina, we saw many, many people walking around the streets, at work, or sitting in parks or cafes with their gourd and thermos; they drink it anywhere and at any time. I've been a fan of yerba mate since I discovered it in high school, so I was happy to replace my old gourd and bombilla with this handsome set we found at a silversmith's shop in Cafayate, in the north of the country. Bonus: we had the cutest salesperson ever.