Sharing music with multiple users?

I'm hoping someone can point me in the right direction. Here is my problem. I have 5 kids that each have their own iPod/iPhone. They all use the same Windows 7 PC, each one with a different user account. I need a way to be able to add new songs to the main library, and then have them show up under all 5 accounts automatically.

My current setup is this. I have 2 hard drives in their computer. The first is the main OS drive, and the second is used for MP3 storage only. I intially setup iTunes under a single user account, and then pointed it to the 2nd hard drive for the music. I then copied that completed iTunes folder to each of the other 4 user accounts C:\User\Music\iTunes folder. This worked and each of them were able to access all of the current songs and sync up without affecting one another.

Unfortunatley this left me with one additional problem. How can I add new songs to the main library and have them be auto detected by all 5 accounts without having to log into each one and manually add the new music? As they get new CD or MP3 purchases, it is a big pain to have to manually do this everytime to make sure they are each seeing all of the music. I know I could setup a single account and not have to jump through all of these hoops, but I want them to be able to check/uncheck and sync their songs the easy way and avoid unnecessary fights! 😉

Any thoughts or suggestions would be greatly appreciated!