iPhone App Installation
No, installing apps 'without asking any permission' is definitely impossible. Attempting to install an enterprise app over the air will prompt upon attempted installation and the first attempted launch of the app. This is un-negotiable.

You can install apps over the air using enterprise distribution. This allows you to set up a 'portal'-like page which people can download the app from. A plist is downloaded to the device informing it of the location of the app bundle and some information about the app itself. For an example of this, see the Stack Exchange iOS app beta. For more information about enterprise distribution, see the guides available in the Member Centre.