Every time you install an application with a traditional installer under Mac OS X, you have to enter your user password first, unless, of course, the installer has no provision for that. And most do.
When you first run an application that you download from the Internet, Leopard delivers another warning, explaining it is a downloaded [...]

With worldwide Leopard coming out parties, and lots and lots of copies arriving the very first day Mac OS 10.5 is out — and maybe sooner if you can believe some reports — you’d almost expect massive upgrades being performed over a period of several days.
This is a vision that seems real enough, although [...]