For lightweight and small this   (You need to Login or Register works very well. I use it by making "cowboy" coffee and then pouring it through  the filter and into my mug. There is also this solution   (You need to Login or Register makes a great cup of coffee (one cup at a time) but is heavier and takes up more space (I use it with a reusable mesh filter rather than a paper filter). Works good for camping or for tossing in your carry on bag with some decent coffee so you don't have to suffer through hotel coffee.