Here I have introduced a Android-x86 build of Ice Cream Sandwich for Virtualbox or VMLite workstation 4 beta, created by VMLite corporation. Now developers from VMLite corporation has released a new and improved build of Android x86 4.0.
VMLite Android 4.0.1 ICS for x86 virtual machines from VMLite Corporation has been updated with these new features: mouse integration with host (no more mouse trapping and pressing right shift key to release mouse from VM window), support for shared folders between Android VM and host folder. There is also a virtual disk emulating a sdcard, that will be automounted. So Android ICS supports 8 GByte sdcard space.
Setup the virtual machine
After unpacking, start VMLite Workstation 4.2 beta or VirtualBox v4. Then go to menu Machine –> Add (or press Ctrl+A) and select Android-v4.vbox file to add the vm. Afterward you should be able to boot the virtual machine.
If the steps obove are not working, it's possible to create a new virtual machine using Machine > New VM and set up Linux 2.6 as guest os, Afterward add the two vdi files located in source folder using IDE controller to the vm. Android-4.vdi should be Master, and sdcard.vdi shall be the slave.
After booting the virtual machine drag the lock using the mouse to enter the Android screen. The sdcard will be automatically mounted. VMLite Forum  contains discussion between users and developers. Articles [a till e] in the link list below discussing, how to use Virtualbox to experiment with ice cream sandwich or use this solution as a fast device emulator.
1: Download Android-v4.7z (VMLite)
2: Discussion in VMLite forum
a: Ice Cream Sandwich-Testdrive in Virtualbox – Part I
b: Test: Ice Cream Sandwich in Virtualbox – Part II
c: Android-x86 Ice Cream Sandwich from VMLite Part III
d: Running Ice Cream Sandwich in VMware Part IV
e: Experimenting with ICS (in Virtualbox, VMlite, VMware)
f: New Virtualbox Ice Cream Sandwich-Build