I often do this, since it can be a hassle to retrieve a given piece of information when I am using many different systems during the day. Mostly, my content is solely in the subject line, and is often just a reminder, or personal note to myself.
This got me wondering: Is there a product here, or could email providers do something special when they notice you doing this?
Create a group with one other member. Delete that member. Now you can send messages (or media) to yourself and only you will receive it. It's useful for storing notes or pictures or whatever...