Here are the simple ways to get vista like top / side bar on Windows XP.
Option 1 : Rocket Dock
Download Rocket Dock bar from http://www.rocketdock.com
RocketDock is a smoothly animated, alpha blended application launcher. It provides a nice clean interface to drop shortcuts on for easy access and organization. With each item completely customizable there is no end to what you can add and launch from the dock.
Now with added Taskbar support your minimized windows can appear as icons on the dock. This allows for better productivity and accessibility.
It is Free!!!
Minimize windows to the dock
Real-time window previews in Vista
Running application indicators
Simple drag-n-drop interface
Supports alpha-blended PNG and ICO icons
Icons zoom and transition smoothly
Auto-hide and Popup on mouse over
Positioning and layering options
Supports many languages and can easily be translated
Option 2 : Object Dock
ObjectDock is a program that allows you to have a nice animated launchbar/taskbar on your screen that reacts to your mouse when you mouse over it. In short, it's a task bar and program launcher that does it with style.
Download from http://www.stardock.com/products/objectdock/downloads.asp#download