Bristols 6 brings a little envelope of awesome to the solution: Their Hem Tape comes in sheets of pre-cut, double-sided sticky strips you can just lift, stick, and like magic, your too-long jeans are suddenly “hemmed” in a flash–no needles or iron required. It’s not a permanent solution (don’t put the tape through the wash!), but it does hold even heavy denim securely, and sure beats rolling your pants up in a pinch.
I also happen to know it works with stubborn tweens bemoaning the geekitude of turning up their dragging hems, too. Thank goodness. -Mir