Android-x86 is a project that has ported Android for PC use.
They offer builds for different systems (e.g. Asus Eee PC, Lenovo Ideapad, etc), but you can also install and run Android-x86 in VirtualBox (PC / Mac / Linux).
Download installation ISO for Asus laptops / tablets (this is the one I used), and setup a new virtual machine in VirtualBox. Installation is very quick and straight forward.