Note: For this tweak I recommend using the ChromEdit Plus extension.
With Firefox 2 came the options of changing where your close tab buttons were displayed along with tab-overflow and the List All Tabs buttons. By default the List All Tabs Button is on the right side of the tab bar. You can either move it to the left side of your tab bar or remove the button altogether.
To move the List All Tabs Button to the left side, simply add these lines to your userChrome.css file located in your profile folder:
.tabs-alltabs-stack {-moz-box-ordinal-group: 1 !important}
.tabbrowser-arrowscrollbox {-moz-box-ordinal-group: 2 !important}
.tabs-closebutton-box {-moz-box-ordinal-group: 3 !important}*Below Tweak does not work with Firefox 3*
Or to remove the List All Tabs Button add this line to your userChrome.css file located in your profile folder:
.tabs-alltabs-stack { display: none !important;}
When you are done editing your userChrome.css file, close and restart Firefox and the changes should take effect right away.
Source:Mozilla Links

