With the right skills, you can port Jelly Bean's Google Now over to your Ice Cream Sandwich Android device. If you want to try the oh-so-creepy predictive assistant, but you're not yet running a build 4.1 operating system, you can do so following a set of instructions posted on the XDA Developers forums.
1- Open Root Explorer & navigate to /system
2- Now Open build.prop in Text Editor.
3- Edit ro.build.version.sdk = 16 & save.
4- Now go to /system/app & Rename GoogleQuickSearchBox.apk to GoogleQuickSearchBox.apk1
5- Now reboot & install the app from the download link. (Mirror here)
6- Now edit build.prop & change ro.build.version.sdk = 15 & reboot.
Now any time you fiddle with your phone, you risk screwing it up. So if you're going to do this, make sure you absolutely know what you're doing. If you do, let us know how it works out in the discussion. [XDA Developers via TechCrunch]