I agree with you on the focus-follows-mouse, and when I got the Mac, I switched my Linux boxes to click-to-focus, just to be a little consistent.
However, if you want to try multi-desktops on a Mac, take a look at CodeTek's VirtualDesktop. I love it, but I find that with Expose, I use it much less than I used to. Expose makes my 1024x768 desktop seem much bigger.
They are called computers simply because computation is the only significant job that has so far been given to them.