In the past, my wife and I just drank out of our BPL Firelite 550 mug after we used it to boil water for FBC. But I'm now thinking of moving to cooking in the pot (and a larger pot), so I'm looking for a separate mug since my pot will be tied up with the food.
My Snowpeak titanium mug weighs in at 31 g on my scale. It has a capacity of 1.25 cups. The great thing about it too is that you can use it as a measuring cup of sorts (although it doesn't have gradations on the side). I could trim off the handle maybe, and get it down to around 1 oz.
Is there anything lighter out there, maybe around 0.5 oz? Something free? I'm thinking cheap disposable cups here. Styrofoam doesn't seem quite durable enough, and I don't like the stuff (it's not healthy).