Where can I find alternative alert sounds for my iPhone 4S? There is a very limited set of Alert sounds in Sounds > New Mail > Alert Tones.

Is there a way to add other sounds to this list? I would like something sort and subtle, not something that goes on for 2-3 seconds.
Your options are:


Purchase tones using iTunes (on Windows and Mac OS X)
Compose your own tone using Garagaband (Mac only) and export to iTunes (on
Windows and Mac OS X) for syncing with your iPhone. 
Create your own tone using Ringer (Mac only) available from Mac AppStore.