For those with a scroll wheel on their mouse, Mac OS has one nice feature that is annoyingly absent in Windows XP. In Mac OS, if you put your mouse cursor over a window and scroll, it scrolls the contents of that window – a document, a webpage, whatever. In Windows XP, it will only scroll if it is the ‘active’ application, and will ignore scrolling when the cursor is pointed elsewhere.
The difference may have to do with some deep mechanism by which Mac and Windows applications interact with the operating system, or it could be a minor configuration choice. Either way, the Windows approach is annoying.
Of course, Apple doesn’t do everything right. My fancy wireless Mighty Mouse is over in a dresser drawer somewhere, too annoying to use. Instead, I am using an old $20 Microsoft optical wheel mouse.