iPhone/iPod TouchI have found the way to permanently delete uninstalled apps form the itunes list of apps... Follow these steps and poof gone form the list.
1.) Connect iphone to PC and open itunes (it should open to your list of music or what was showing when you last closed it)
2.) Make sure in the upper left corner it shows Apps and not something else
3.) Across the top you should see about 5 choices, "All - iPhone/iPod Touch - iPad - List - Updates"
Select "iPhone/iPod Touch"
4.) hold down the ctrl button (windows) and begin to click the ones you want to delete to highlight all of the apps you want gone.
5.) When you finished selecting al the apps you want to delete, press the delete button and confirm.
6.) close iTunes and disconnect your device and reconnect and start itunes. apps in the list should only show what is physically on your device.