Blogger.com has a favorite icon that so familiar with us.
if you want to customize this icon,
please do these steps below :

1. Create your own image. You can create it in any format and in any size.

2. Change your image format to be *.ico . You can visit http://www.favicon.co.uk/ to change your image format.

3. If your image is already formatted in *.ico , so you don’t need to change your image format anymore.

4. Once you’ve got your image formatted in *.ico, then publish it. The problem is most image publisher site doesn’t support to publish an image formatted in *.ico, but you can upload it in googlepages, you can login with your gmail account.

5. If you didn't already have gmail account, you must register your name first.

6. Don't you name your favicon as favicon.ico. Use the other name like sangdedi.ico or etc, it's because if you name your favicon as favicon.ico and you upload it in googlepages, it will reffer to favicon of googlepages.

6. Last action is add this code to your template

<link rel="shortcut icon" href="http://myfavicon.com/sangdedi.ico"/> <link rel="icon" href="http://myfavicon.com/sangdedi.ico" />

Change http://myfavicon.com/sangdedi.ico with your own URL
Put it before tags </head>

P.s: The best favicon size is 16 x 16px