ginkgo found a recipe for cold brewed coffee, and I made some.
This isn't coffee, this is coffee concentrate. Same amount of grounds and water as when I make a hot french press full, but holy crap. I looked at the lack of opacity in the resulting liquid, and thought "Lame. This looks really weak." Ha! I enjoy chewing/sucking on coffee beans directly, but I might have to dilute this a tad. Yikes.
Goes well with a squirt of simple syrup however. :)
Edit: When you pour the water over the grounds, cover them airtight. Air during the brew process leads to bitterness. I use the french press still, and just put Saran Wrap over the carafe. Pop it in the fridge at night, press it in the morning, enjoy chilled smooth brew.