I have a new iced coffee technique to use at work. Long story short, I put an ice cube in the mug, then get a single shot of hot espresso over it. Melt the ice by stirring, then sweeten and add milk to taste.
I tried "New Orleans"-style cold brewing in a jar overnight, but it was too weak for me. I prefer the stronger taste of espresso, which I used to cool with milk after the sugar dissolves, but cooling with ice immediately seems to make it taste even better. The down side, of course, is that I need to prepare ice at work, which is a pain, but not impossible. And if I run out of ice, I can still fall back on milk-cooling. If you're an iced coffee fan, I recommend giving this method a go.
Mokalus of Borg
PS - I tried a couple of times to use milk ice for this, but it didn't work so well.
PPS - I've heard this is called "Japanese-style" iced coffee.