Sure sure, they make single cup brewers, as well as over the mug doodads that do exactly this. This, however, was FREE, made of stuff sitting around. Figured I would share. This is my first instructable, be gentle with me.
Two toss-away coffee cups
Paper coffee filter (basket type is probably easier to use than the "wedge" style ones
Coffee (whatever sort you'd use to brew drip coffee, in my case, Folgers is what we keep in the cupboard, and since this is all about being cheap, it'll do)
Rubber band or paperclips
HOT water (a little more water than you want of a final volume of coffee)
Knife or other cutting instrument