Get the SnowFall screensaver for OS X
Russell Warneboldt (code) and Wilson Bentley’s (pictures) SnowFall screensaver is the best looking falling snow screensaver for the Mac. This Quartz Composer-based application (you can’t get more native than that) is Snow Leopard ready and is a very pleasant face and affectation to display on your Mac.
SnowFall is a great way to get in the mood for Winter and the holiday season of giving.
Also for your Mac customization pleasure, check out these articles:
— Christmas: Top 5, best holiday screensavers, icon sets for OS X 10.6
— Mac apps: Top 10 + 3, best OS X screensavers
— How to: Star Trek sounds on your Mac
— How to: LCARS for Mac
— How to: Change icons on your Mac