Labnol has a great tutorial on how to master the secret features of your iOS keyboard.
I used this today in order to enter a degree symbol in text. Hint: it’s done by shifting to numbers, and holding down the zero.
Another great hint: When typing an email address hold down the period key and it will pop up with .com,.net, and.org extensions to make your thumb squee with joy.
What’s your favorite iOS keyboard shortcut?