Windows: If you want to mess around with reskinning your Windows 7 or Vista taskbar without having to muck around with patches, AeroWorks is a no-fuss method for skinning the taskbar without modification to your system.
AeroWorks swaps out the taskbar background and special effects with those of the seven included skins. You can combine your own images and special effects by clicking on the Choose Base and Choose FX buttons in the upper right hand corner.
It doesn't patch or modify your system beyond changing the appearance of the taskbar while the application is running. If you don't like the changes you can undo them within the program and try a new skin or simply close the application to revert the taskbar to its default state.
AeroWorks is freeware and requires Windows Vista or higher. Have a favourite tool for skinning Windows? Let's hear about it in the comments.