While browsing on your iPad you may have to enter a URL followed by .com, .net, .org, etc. Rather than changing the keyboard to add the dot, then hopping back and typing out the three letters you can simply hit the .com button. Obviously, right?
But what some may not know is that if you hold down that key, you will notice other often-used extensions there, such as .net, .edu and .us. This can be a quick timesaver when looking for a particular website that doesn't end in a traditional .com.
On that same note, you can hold down various keys on the keyboard to bring up new characters you may not have even known you were able to type. For example, holding down the N key will also bring up the √ë. This works with various other letters of the alphabet that may have accents in other languages.