Where iTunes actually store iPhone apps and their data on Mac

In your iTunes library along with all other iTunes content on your iPhone.
To view all apps in your iTunes library, select Apps under Library in the iTunes source list. To select the apps in your iTunes library to be installed on your iPhone or to be removed from your iPhone, check under the Apps tab for your iPhone sync preferences with iTunes.
Data created and stored by a 3rd party app on your iPhone is not stored with the app in your iTunes library on your computer. 3rd party app settings and data created and stored by a 3rd party app on your iPhone is included with your iPhones backup which is updated by iTunes as the first step during the iTunes sync process. Your iPhones backup is not stored in your iTunes library.
http://support.apple.com/kb/HT1766
 MacBook Pro 15" Intel Core 2 Duo/2.53GHz/4GB RAM/500GB HD Mac OS X (10.6.6)  iPod w/Video 30GB,  iPhone 4 32GB

Thanks but I was referring to WHERE, LITERALLY, on the HD, i.e. what is the path. I found them.
The APPS are stored here on my mac:
Users/user_name_here/Music/iTunes/iTunes Media/Mobile Applications
It looks like the data for these apps is stored here:
Users/davekees/Library/Application Support/MobileSync/Backup
It also looks like its encrypted, hopefully compressed.
I plan to DELETE the contents of these folders. I load apps onto my device all the time, and then I delete them after a while. I definitely dont want them to be backed up. This is the only SAFE way I know of to get rid of apps. I dont trust iTunes, accept for backup and restore. Cant use it to arrange my apps. It cant handle everything I have.
iPhone OS 3.1.3