How to Hide Folders in Android Mobiles

I gave some files to my friend to hide it in his mobiles but it has displayed in the gallery because its an Android mobile, So i tried for any hack tricks to hide folders in Android OS Mobiles ,then i got this Simple Trick ... So follow my steps & try it in Android Mobiles 

Step 1 :  Install a file manager in your android phone by using the Android market and search for file manager and install anyone.

Step 2 : Open the File Manager and Goto the folder you want to hide ( even any single file also you need to keep it in a folder )

Step 3 : Now Rename the folder you want to hide with "." Ex: ".name" instead of "name" 

Step 4 : You are done , Android gallery and video player won't recognize that folder anymore.

Step 5 :  If you want to unhide it, then rename the folder and remove the "." Ex: ".video" to  "video"