Whenever I install a piece of software (most recently msn messenger, firefox and thunderbird email client) it installs, comes up in the dock, then an annoying icon appears on my desktop, I don't mind it when that happens when you put a CD i nthe drive or log onto a network server but if that happens whenever I install a program and go to use it i'm going to have loads of them on me desktop. How do I install/run a program without it putting this icon on my desktop? I've tried putting the .dmg file into applications first then installing it from their with the same result