I buy Mio drops to add to water for flavor. They come in these cute little containers. I hate to toss anything if I can find a way to recycle so I washed them out and saved them. Now I use them for the condiments (catsup, mustard, etc) when packing my husband's lunch or when we take food along on trips.
They are also amazing for travel toiletries. I use them for lotion, shampoo, oil, dish soap, etc.