Here is a quick and easy way to send secret messages or files to your friends using just a common .jpeg picture:

1. Create a folder and put a .jpeg picture file in the folder. The picture can be anything you wish. Note the path to the folder (c:\foldername)
2. Open notepad and type your message you want to send. Save it with whatever name you want. To send a file, select the file you want to send.
    Use Winrar to create a .rar file with your message or file.
3. Put the .rar file you created in the same directory or folder as the .jpeg picture in step one.
4. Open a command prompt ( Start-> run->cmd)
5. In the command window, navigate to the folder you created (cd c:\foldername)
6. In the command prompt window, type /b nameofpicture.jpg + nameofrarfilecreated.rar  nameofcombinedfile.jpg
7. Double-click the "nameofcombinedfile.jpg" you just created and it will open as a picture.  Right-click it and choose "open with" Winrar, however, and you
    will see the files you hid inside the picture and can extract and save them.
8. You can even zip the nameofcombinedfile.jpg, and password protect it if you like.