Here is one simple thing that many companies do while their customers are on hold. They advertise! When the automated attendant answers and you choose the option to get to the right person you sometimes have to wait. During that time, instead of playing the latest top 40 hits, many companies advertise their products and services. This a great way to promote your goods to a captive audience! let me encourage you to use your on-hold time to advertise what you have.
There is something that I have noticed recently that is a little disturbing. First, many people are starting to use cell phones as their primary business phone. The problem occurs when people use the on-hold music as their wait "entertainment". You call them and instead of hearing a "ring" you instead hear "please enjoy this music while your party is reached". You then hear the user's favorite tune - which most of the time I am not interested in.
If you use your cell phone as a business phone then please reconsider this technique as it makes your business sound cheap, extremely small, or somewhat childish. You do not want to have your first impression as being unprofessional. If you use your cell phone as your business phone, make it a point to answer every call unless it is impossible to do so. If they have to go to voice mail, leave a professional message and if possible leave an option to hear some of the latest specials.
Use your phone system to benefit you, not destroy you.