If you're looking for a great gift idea for under $15, check out the Insulated Mug from MSR. It comes in a variety of colours, nests in cooking pots, and in turn, you can also pack gear inside them such as a PocketRocket 2 Stove. It is made from Stainless Steel, which means it is great to hold hot meals, and you won't have to worry about chemicals leeching into it. It is also wrapped in a grippy EVA foam coating to protect you while you sip your morning coffee through it's protective BPA-Free insulating lid.
It's the perfect mug for camping, holds .37 liters and weights 111 grams.