Whenever I go camping I carry 2 stainless cups - 1 nests with my nalgene; and 1 military canteen cup with nesting stove stand, which also is the perfect size for my backpack's side pocket and for holding survival gear. The nalgen cup I bought because it was cheap and nesting, and incidentally the bottom(both inside and out) is shiny enough to work as a mirror(both regular and signal, although I've never tried it as a signal mirror).

I carry a second cup so I can have tea or other hot beverage while using the other as a bowl(and not getting my nalgene dirty, although it would probably be fine for tea). I also like the nesting stove stand, although I've never really used it(except as a radiator to cool down a hot beverage-I think it's made of aluminum) and I honestly don't how well it would work without solid fuel. Having a second boiling container can be valuable in a survival situation, to purify twice as much water in the same time, or to use one as a shovel, hammer, collecting wild food, etc., even carrying coals or a small fire if you don't have matches. I also often travel with inexperienced or unprepared people, and an extra cup is always handy.
Eventually I will probably replace one of them with a titanium cup, mainly for the corosion and heat resistance, but not until they become cheaper or I become richer.

I also have doubts about the strength of titanium, I don't know if it can stand up to the abuse of survival or even regular use, especially if improvised for some of the above purposes. There are many misconceptions about titanium, and I'm a bit unclear on it myself. Saying that titanium is simply stronger than steel is meaningless, unless you define what you mean by "stronger". Remember that titanium is 40% as dense as steel. With an equal weight of titanium and steel, titanium is stronger, but several times the volume. At an equal strength, titanium is about 45% lighter. What about at an equal volume? This may be the most important question for general use, and I'm not really sure the answer. According to this site, titanium is half as strong(and half the weight) as steel for a given volume . This would explain why it is almost never used in knife and sword blades, where volume is critical.
The point is that titanium is not a miracle metal. It can be stronger, lighter, or both, but also weaker and lighter, than steel. It all depends on the volume, and of course alloy. As far as titanium cups go, the volume seems about the same as other materials, so it is most likely weaker than steel. Sorry for the rant, but I hope I corrected some myths about titanium.