If you're new to AutoCAD or even if you're not and you find it difficult to remember all the keyboard shortcuts to your favourite commands like L for Line and C for Circle or even 3DO for 3DOrbit, then you need to know about the AutoCAD Alias Editor.
Enter ALIASEDIT at the command line and AutoCAD will launch a tiny application window that lists all the shortcuts in alphabetical order. As this is a seperate application, you can keep it minimised on your taskbar until you need it for reference.
Essentially, this editor simply lists the contents of the acad.pgp file where all the command aliases are stored. Those of you who are a bit more adventurous, may even like to use the Alias Editor to create your own aliases or edit existing ones.