Google Desktop and Sidebar
Read more about it in the NYT article 'Google Gets Better. What's Up With That?'. An audio slide show is available.
Don't forget to choose the Auto-hide option, this way the sidebar will be out of your way when you don't need it.
The new IM/VOIP client, Google Talk, can easily be embedded in the sidebar by using the Add/Remove option. Google Talk already has a Wikipedia page.