Its amazing how many people use Vista and don't know about its key feature - the mighty snipping tool. Its amazing!
Its installed by default in All Programs, Accessories, Snipping Tool and the first time you run it, it asks you if you want to put a shortcut to it on your start bar - that's because the guy who wrote it knew something you don't yet - that the Snipping Tool will change your life.
You run it and it freezes the screen where it is and lets you draw a box to take a screenshot of a bit of it. You can even use a highlighter pen on it without the drawback of getting ink all over your monitor. It does by default put a big red border round the screenshot which is easily disabled, but this is my only gripe.
Personally I think Microsoft should market Vista as "The only Operating System with the Snipping Tool" - I'd buy it!