The sound that about a thousand tacks of various sizes make, as they hit the deck because you've knocked the box over. Not only do I now need to pick the darn things up, they need sorting as well.... A very irritating sound.
I rarely use e-mail for letters. I prefer to send hand-written letters, especially if they are of a personal nature. My young friends get cartoons drawn in their letters by way of illustration, the grown ups just have to put up with more of my waffle.
Sending a letter also conveys your fondness for the recipient, just by the fact that you have taken time and care over the letter.