With voice search it really gives Siri a run for its money, and it's quite adept at smartly answering questions. If you're not planning on picking up a Nexus 7 tablet, or simply don't want to wait for yours to arrive, there are now a couple tricks you can use to get Now running on an Ice Cream Sandwich device.
Getting Google Now up and running on ICS requires multiple edits to build.prop and some file renaming. It's not too complicated, but if you don't want to risk any missteps, there's a simpler option available. For that, you'll install a modified Google Now package that's already configured to ignore that you're not running Jelly Bean.
Even with Now running, things aren't quite perfect. The voice component of the search reportedly isn't working at the moment, putting a bit of a damper on how interested you may be to install it. Users are also running into other errors concerning network connectivity and an inability to gracefully exit the app. Lastly, there's the issue of ROM choice to consider, with pure AOSP-based builds causing the fewest problems.