Normally with the online Apple Store, a minimum of $50 is required to get free basic shipping. However, today a purchase of any monetary value will be eligible for Apple's free shipping: "Get free shipping on everything. Today only," the company's virtual storefront reads.
If you know what you want from Apple for the holidays, and you didn't indulge in their Black Friday promotion (up to 10% off most major items), today would be a good day for buying, particularly small stuff like the Apple Battery Charger, the Apple Remote, or one of the myriad cables they sell. If you're getting an iPad for the wife or iPod for the brother, though, it really doesn't make a difference because those always ship for free.
Apple also has gift packaging available for $5 but it's not really worth it unless you don't have thumbs or otherwise despise wrapping presents.