I've been thinking about getting a Vargo Ti-Lite Titanium Mug. It fits over the end of a standard 1L Nalgene bottle which saves space. It weighs 5.2 oz yet holds .75L. By contrast, the USGI Canteen Cup weighs 8.96 oz and holds .7L. Yes, that's "only 4 oz," but think of it as a quarter pound -- save a few of those and you've got a pound, it really does add up ... just ask my back.

I've seen them for about $30.00 which is a little pricey, but not that bad.

One of the advantages of the Nalgene bottles is their wide mouth which facilitates the ingress of snow. In spring conditions, one can scoop snow into a half full of water Nalgene, hang it on the back of your pack, and let the sun work it's magic. I got about a quart of water that way in one afternoon on a hike I did last April. A quart is enough to make a big difference -- just ask anyone who's brought three quarts on a hike and needed four. In this case it turned out to be a lifesaver; I would have gone dry because the hike took longer than planned due to the heavier than expected snow.

When it's colder or overcast, I'd use the mug for melting snow, but it's still to my advantage to have a wide mouthed bottle that is easy to pour into or use as a snow holder as I add more snow to the mug during the melting process (the amount of snow you can stuff into a pot is only about a third of the capacity of the pot once is turns to water.