The following is not a hint, really, but an observation of a cool non-publicized Snow Leapord feature.
While flying home from the west coast this holiday season and changing the time zone on my MacBook, I noticed a new feature on the map that you see in the TIme Zone tab of the Date & Time System Preferences panel: The map of the Earth changes based on the time of the year.
For example, if you set the month to August in the Date & Time tab of the panel, the map will display a lush green northern hemisphere. Setting the date to December changes the northern hemisphere to the appropriate snow cover.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20091222235526575