Make your own icon for the tab bar of Browsers.

Its easy.
Download IcoFX from portableapps.com. or another ".iso" Icon editor.

Make an Icon.
Choose a simple image or logo you have.
-Its as easy as dragging an image into the program.
-Set size to 16X16, True colour + Alpha channels
-Let the creative juices flow.
- View at 100% and save a backup copy.
- Now save a copy called "favicon". This is the file you will copy to your site folders.

Icon made.

- To Change the favicon , you must replace favicon.ico file in templates/[template name] folder . Or just drop one in. Some templates don't have one.
-If you do a search of your site you will find all your favicon.iso files. These are the ones you need to replace with your file.

Done. I went with a paw print.