While surfing around the net last month, I've found this very nice Mac OS taskbar emulator for Windows. Named: "RK Launcher" – this is a free application that will allow the user to have a visually pleasing bar at the side of the screen that is used to quickly launch shortcuts. With support for themes, PNG's and ICO's and with smooth amazing animations, RK Launcher is a versatile and great taskbar replacement.
All parts of RK Launcher can be customized.
http://home.cogeco.ca/~rklauncher/

Heres my screenshot:

I've been using this for a month now and it works great. Although I'm not an expert I can assure you that RK Launcher is a must have application for your desktop. I recommend using RK Launcher and Style XP for full Desktop Customization.

Style XP is not a skinning engine. It uses Microsoft's built-in visual style engine, but enhances it by providing many useful tools. Style XP can import, select, rotate, and manage themes, visual styles, wallpapers,  logons, bootscreens, icons, and explorer bar. Future versions may support sounds, cursors, screensavers, and packages of all the above. How does it work? Instead of lines and gradients, the XP user interface natively supports the use of skinned bitmap controls (a visual style). This is Microsoft's own innovation. Style XP includes its own visual styles. www.tgtsoft.com