Howtoforge posted a guide about making an Ubuntu 10.04 Desktop resemble a Mac
This article shows how you can change the appearance of your Ubuntu 10.04 desktop so that it resembles a Mac. This can be achieved with the help of Elementary, Docky, and Gloobus-Preview.How To Make An Ubuntu 10.04 Desktop Resemble A Mac (With Elementary, Docky and Gloobus-Preview)
Elementary is a project that provides a popular icon set and GTK theme; Docky is an interactive dock (like the one you know from a Mac) that provides easy access to some of the files, folders, and applications on your computer, and more; and Gloobus-Preview is an extension for the Gnome Desktop Environment designed to enable a full screen preview of any kind of file or directory.