OK so you've deployed Windows 7 to your clients and you have not given them local administrator rights (damn right in an enterprise environment).
However non administrator rights means no printer installations without a UAC prompt for admin credentials - which can prove a thorn in the side, especially if your users move around a lot and need to install printers at various locations.
This can be addressed via group policy.
I have managed to allow non-administrators to install network printers on their local machines by applying the following single GPO which apply these two settings:
Computer Configuration -> Policies -> Administrative Templates -> System/Driver Installation
Allow non-administrators to install drivers for these device setup classes = Enabled
Allow Users to install device drivers for these classes:
Computer Configuration -> Policies -> Administrative Templates -> Printers
Point and Print Restrictions = Disabled