Typography and punctuation geeks rejoice! It's easy to type an em-dash on the iPhone's or iPod touch's virtual keyboard. To do so, tap the .?123 key to switch to the numeric keypad. Then touch and hold on the Hyphen key to reveal a pop-up strip showing an em-dash. Slide to the em-dash and release your finger.
Note that this basic trick works with many other keys on the virtual keyboard.
From Tonya Engst