<p>Where do you want the shortcuts? If you drag a program to the dock, it will sit there, not making a copy, but be ready to open with the click of the mouse.</p>
<p>I don't like tabs for AIM conversations. When IMs pop up on my screen I can usually tell who it is by where the window came up w/o reading the name. =P Maybe I just don't like tabs in general though, because I don't use them with Safari either. Don't need to with Expose.</p>
<p>I also recommend a multi button mouse. Actually, TODAY, apple came out with a new mouse that's quite awesome. Instead of just scrolling up and down, you can scroll diagonally with a scroll ball and it senses clicks by pressure.</p>