Like many people do on ubuntu. Is removing the top bar and put it all down. I will write here how to do it for this theme.
Download and apply the SlicknesS theme.
Download the file, Extract to your home/.themes directory. Apply the fixes within the comments.
Delete the Lower panel. Right click on top panel and click "New Panel"
Now you got a clean/whiped ready to be configured. Right click on the Lower panel and go to "Properties" Adjust the panel to 34 pixels in the "General" tap.
Add a "Main Menu" to your panel by right-clicking on an empty area on the panel and selecting "Add to Panel". There are two types of menus there -- you want to pick the one represented by a single icon of the Ubuntu logo (or whatever your Linux distro uses as a default image).
Now add 3 Separators 2 next to the Gnome logo and one on the right. Leave about 2 inches space left from the right.
Between the 2 separators put your browsers/email applications. And move on to the right side.
Add over there: Clock, Volume Control, Network Monitor and Notification Area.
Order them in line as you like and don't bug your self about it.
Were heading back to the "Left Side". Add there next to the 2nd Seperator: window list.
Congrats you got now a windows look like task bar.
Download a menu icon. For this example i used the one from "Dark Ice" Theme.
You can download the "Menu" and the "Bar" from my photobucket.
Save them in your ".themes" folder in your home directory.
Set the custom menu graphic, you need to open the Configuration Editor under the "System Tools" menu -- or for you hardcore types, "gconf-editor" at the command line. Go to apps->panel->objects and you'll see a series of object_x subitems. Click through them until you find the one where the value for "object_type" is "menu-object". Check the "use_custom_icon" option and then set the "custom_icon" value to the path to your custom button graphic, i.e. "/home/username/Pictures/menu.png". The graphic should update immediately.
To use the costum background as well. Right click on an empty space > Properties > Background > Use background image. And browse to "panel-bg-black.png"
Tested this on: Debian Lenny/sid
AnsheShem -- For his awesome Menu button.
TheRob -- For his SlicknesS theme.
natewelch.com -- For his explenation to do all this.