Google has announced the avialability of a Google Pack which contains a collection of must haves on any respectable PC. Some of the important ones include the Google suite (Google Earth, Google Picasa, Google Desktop, Google Toolbar for IE, Google Talk) and Other including Firefox, Norton Antivirus, Real Player, Trilliam (a hybrid Instant Messenger), Ad-aware (Anti-spyware), Adobe Reader 7 and a Google PAck screensaver.
In case you already have some of those, you can omit downloading those.