Unlike all of the highly touted features of Vista like UAP, Glass, IE7, and Speech recognition, one of my favorite and IMHO most useful features is probably staring you right in the face and you may not have even known it. Its called the Vista Audio Mixer and it allows you to customize the relative volume of every application running on Vista. Before you can use it, however, you have to turn it on as the default in Vista is for sound to work just like previous versions of Windows. This is easily done just by clicking on the volume icon is the task bar and select the box that says use audio mixer. Once this is done, the next time you lick the volume icon you will see a separate slider for each application that it currently running.
What does this do for you? Well if you are like me you run many application and some might have annoying sounds (like a game) and not give you an easy way to control the sound level (other than the general windows volume). With sound Mixer you can turn down those annoying sounds of cards shuffling in Hoyle’s card games to a whisper and still hear the general effect while listening to Baroque Guitar in Media Player at full volume.
It may not seem like much, but it is a great little feature that make Vista a pleasure to use and explore. Now if they could just make the user interface consistent, and get more complete and available drivers for 64 bit all would be right with the world.