Normally, it takes 3 steps to type punctuation with the virtual keyboard of the iPhone. First the “.?123″ key, then the punctuation or number key(s), then the space bar will return you to the QWERTY keyboard. Pogue has a great shortcut that reduces the previous to one key stoke or press:
1. Touch the “.?123” key, but don’t lift your finger as the punctuation layout appears.
2. Slide your finger a half inch onto the period or comma key, and release.
Actually you can slide your finger to any key, not just the near ones.