Evernew's EBY-265 Titanium Cup 400 is an ideal size made from an ideal material for sipping. Titanium doesn't conduct heat as well as steel so you're less likely to burn your lips.
Evernew says: Ultralight titanium cup
400ml is a decent cup of coffee and you can even heat the water in it. Silicon insulated handles complete the package - but don't burn your lips if drinking hot liquids, although Titanium is a good material to avoid this. As with all Evernew pots the Cup nests well with other Evernew products.