if you create a blog using blogger.com service will display the default icon blogger will decorate your blog name in the address bar of your browser. To replace it easy enough. You can just add the following script on the script some of your blog template. Here are the steps

1. Login to your blogger
2. Then select the design - the edit html
3. Search
4. Then before the code is type the following script

<link href='http://msp244.photobucket.com/albums/gg19/MaxineLemonade/monkey.gif' rel='SHORTCUT ICON'/>

5. Replace http://msp244.photobucket.com/albums/gg19/MaxineLemonade/monkey.gif with the image url of your choice

• use an image with size 32 x 32 or 48 x 48
• url can be found by searching your favorite pictures in image.google.com or you can upload your own pictures on sites like photobucket or something else and then get the address of your image file

6. After that click save template and then see the display icon of your blog.
7. Good luck!