If you have activated the option to store passwords in Mozilla Firefox, than you can easily look at all password you have entered when you were browsing websites.
You deleted everything from your USB key or a drive, so there should be enough free space to copy the new files, but you still get the not enough free space message in Mac OS X? This is what you need to do.
Google Docs or these days Google Drive can make collaborating with your colleagues or friends much easier by sharing Google Document, Spreadsheet, Presentation, Pictures or a whole folder.
If you are sick of all the stuff a certain Facebook Page is feeding you or you just don't like the brand anymore, this is how you Unlike Facebook Pages.
If there is a vast number of unimportant unread emails accumulating your Gmail inbox and it's starting to bother you, but you don't have time or nerves to mark them as read page by page, this is what you can do.
You have more people using one computer and you don't want them to be able to shut it down using a shutdown button on Windows logon screen, this is how you remove it.
Gmail predicts which emails might be of high importance to you so it marks them as important with a yellow icon. If your inbox ends up full of so called important emails, this is how you disable this feature.
A bit longer Photoshop tutorial, but still very suitable for beginners, where you will learn how to carve a random text into human skin from scratch and make it look realistic.