UltraShredder deletes sensitive files by overwriting them with random characters, saving it to disk each time, and then bypasses the recycle bin, thus acting as your personal, portable file shredder. It is a freeware file shredding application that's light on system resources, portable and well-designed.
Here are some screenshots to illustrate the features and user interface of this application:
Glary Tracks Eraser
Blank And Secure
Secure File Deleter
Wipe
PrivaZer