Microsoft Private Folder 1.0
One of their latest tools is called Microsoft Private Folder 1.0 and it's actually pretty useful. We all have files we wouldn't want anyone else to see, whether it's your tax returns, the suggestive photos you took of your SO, or *ahem* something decidedly naughtier.
Private Folder gives you a folder in your Windows user account that can be "locked". Anyone trying to access it will have to enter a password of your choosing to get in. You can store all the stuff you want to hide in this folder. It also puts a shortcut to the folder on the desktop, like the My Documents, so that you can reach it easily. When you enter your password and unlock your folder, you'll be able to freely work with the files, moving and deleting and opening them in your programs. When the folder is locked, any attempt to access the files by another program or app will prompt you for the password. It has a few other nice options as well, including the ability to automatically relock the folder after a period of inactivity, which is good in case you're forgetful and fail to lock your folder back up when your done using it.