We mentioned the Problem Steps Recorder blackbox error reporting app back in our Win 7 Giz Explains, but it wasn't until I tried it for myself that I saw just how amazing it is.
The quick summary of PSR is that it's a recording app you activate to record any inputs you make to your Windows 7 machine (mouse clicks, keyboard presses) along with screenshots of every step. When done, PSR generates one big HTML slideshow of all your actions complete with an English language description of what you did.
This is great for developers and tech support so they can see what an end-user is doing without actually standing over their shoulder or VNCing into their machine, but it's also useful whenever you have to tech support your parents over the phone (like John Mayer). You can just have them record the steps and you'll view it at home, seeing EXACTLY what went wrong!
Seriously, this is awesome, Microsoft. Now let's have it in every OS please.