I work for a radio station and we have an automation system that stores and plays a lot of our music. Sure it costs a lot of money and has a lot of functions and features, but iTunes has similar features on a much smaller scale.
Many songs, whether downloaded from iTunes or uploaded on from a CD, have a slight gap of dead space at the beginning of the track (like .25 or .50 seconds) and a much longer gap of dead at the end of the track - especially if the music fades down. When driving in your car and listening to your music through your iPod or iPhone, it seems like several seconds of dead space - even when you have "Gapless Album" selected for all of your songs.
One feature that our radio station automation system has is a feature called "AutoTrim". In the master settings of the automation system, you select a db level - for this example, let's say -25db. When you put a song in the automation system, whether manually or with multiple tracks, the automation system will "AutoTrim the beginning of the track (the head) and the end of the track (the tail) - and will stop as soon as the audio reaches a volume of -25db eliminating the dead space at the beginning and end of the track.
I would like an application for iTunes that will do the same thing. Currently in iTunes you can manually adjust each song when iTunes will start the song and when it will end - and you have to do it by listening to it, not by a set db level. I would like the application to automatically do this - for individual songs or in bulk with an adjustable volume setting (which in our example was -25 db).