A few buttons on the side of the doorbell allow you to adjust the volume, select the ringtone, change the light color (or turn it off), or even mute the doorbell. To choose a ringtone you simply press the ringtone button -- it plays the next one, and if you don't like it press again for another one. The doorbell comes with eight ringtones built in, and when you press the button the ninth time it plays the first MP3 you have copied.
I admit I played with the light colors, but ended up with the default setting. We're not usually where I installed the doorbell, so the lighting is fairly irrelevant to us. But occasionally we'll see it and it will give us a laugh. As for sound quality, it is surprisingly good. It is plenty loud, but you can adjust the volume if you need it to be softer. It doesn't play the whole MP3, so you may want to edit yours to get the portion you want it to play.
The first time it rang my wife and I were in our family room with the door closed so we wouldn't hear the party our son was having in the other room. All of a sudden we heard loud singing, and we wondered whether it was somebody's cell phone. I went out into the hall, where someone was standing next to the front door with a befuddled expression on his face while Otis crooned, 'Let me in, let me in...' My response was 'Open the door!'
We had a good laugh, and my wife suggested we could install 'Knock Three Times' by Tony Orlando and Dawn. I also have 'Open the Door, Richard' by Louis Jordan and his Tympany Five waiting in the wings.
You can connect accessories to this doorbell, including buttons on your other doors, motion sensors, and sensors that detect when doors or windows are opened. You can even program a 'secret knock' that plays a different tone if the person pressing the button knows how to activate it. I only have the one button that came with the unit, but I have read you can assign unique ringtones to each button so you will know whether to answer the front door or the back door.
When the batteries are low, the doorbell flashes a signal. Honestly I think it would be better for it to simply say, 'Change the batteries... change the batteries!' because who is going to remember what yellow flashing lights means when the batteries (allegedly) don't have to be changed for up to five years for the doorbell and two for the button?
The Honeywell RDWL917AX2000/E Series 9 Portable Wireless Doorbell goes for about $49. It certainly meets my benchmarks of simple and fun, with a couple of minor dings on the 'simple scale' for using C batteries and for the low battery indicator. But those are very minor complaints. Bottom line: this item makes it easy to put a doorbell anywhere in your house without any wiring. Then it just works.