Important

I have recently uploaded the initial release for the successor (replacement) to Extra Bars called Button Forge. Button forge addresses several of the problems present in Extra Bars (such as Companions sometimes causing an error at first login, poor performance in certain scenerios etc), perhaps the biggest change is the ability to create as many or few bars and buttons as you choose. I encourage you to take a look:

http:wow.curse.com/downloads/wow-addons/details/button-forge.aspx

Note: I have uploaded a v4.0.1 compatible version of Extra Bars now! (I only plan to provide basic support for this addon, but I will try to keep it operational for the time being... I may have a longer term plan if I find the time at a later date i.e. Extra Bars using the Button Forge engine which is a better engine)

(Both addons can operate side by side if you just want to give it a try)

Overview

Adds 4 extra action bars designed to work and look like the standard action bars. These bars are intended to complement your existing UI.

Features

4 additional action bars are added which allow upto 12 buttons per bar
Designed to be quick and easy to configure
Does not change or alter the standard action bars in the game
Bars can be dragged anywhere on screen and orientated horizontally or vertically
Non actions can be dragged to the bar to allow counts of items
Should also be compatible with Bartender, Dominos, macaroon, etc...

Upcoming in v0.8

/ command's for configuration
Option to fully hide faded gui control
'Conditionals' for bar visibility (will allow bar to be shown/hidden during combat etc)
/ command to change the strata level of each bar (controls if the bar will appear above or below other gui elements)

Instructions

These buttons work with the standard drag and drop of actions
A faint icon can be found at the top right corner of each bar, clicking this will provide some quick graphical options to configure the bar including a shortcut button to the bars configuration page
To change configuration settings go to the Interface->Addons->Extra Bar menu option
To bind keys to the buttons go to the 'Extra Bar' section of 'Key Bindings'

Known Issues

Macros with identical names may be switched around on the bar
Critters and Mounts do not darken if they cannot be used
Some spells/abilities may not have a fully updated display on the button (e.g. Hunter Aspects only ever show the skill icon, they don't change to a wisp icon when active)

Feedback

I appreciate feedback and comments you have. Free time to work on this addon is tight, but I will try to put priority behind any significant issues that crop up provided I can confirm them.