Tragically that cup has failed many people. It's not a single piece of aluminum, but a rolled piece with a vertical seam and a rounded horizontal seam for the bottom. It's welded together in a similar fashion as tin cans. The welds eventually melt away and it falls apart. I think there's a few pictures on a couple blogs and maybe a few videos. I last saw them maybe 3 years ago. One guy it melted right away and the other guy got about a handful of campfires in before the seams gave way.

If they made it in stainless steel...it'd be ideal for many things.