Low compression JPGs sacrifice small bit of clarity for an image that takes up less disk space. For example, a high quality JPG of 20kb might only be 3kb as a low compression. Technology's pretty neat, if you ask me. For the most part, you shouldn't use them. Occasionally, the backgrounds aren't bad.
Little bullets can be just fine.
Never use the icons. No one wants to see another dumb email envelope. No one has ever sealed an email in an envelope. If someone has, they would never admit it, even when tortured. Navigating Dumb Libraries 1 .