OnMyCommand allows commands to be added to the shortcut menu. Unfortunately, I can't add them to the services menu or add a keyboard shortcut for them. Is this possible?
Use Apple's automator and save the result as a service. If you select the right conext for the service it will appear in the right click menu. You can add shortcuts to services using System Preferences > Keyboard > Keyboard shortcuts. Click somewhere to the right of the service name (near the right edge of the white box). A field appears and you can type a shortcut. This is not very intuitive.