You fill it about half full with whipping cream, set off a compressed gas canister, shake for 4 minutes (I pretended I was exercising), and you have pure whipped cream, without the preservatives. It's possible to flavor the cream, but I haven't tried that yet. Whiskey flavored whipped cream sounds delightful. I'm sure I saw that mentioned on my "foodie" twitter list.
Here's a photo of chocolate chip/hemp heart cookies made into a sandwich with whipped cream center. (I used the standard Nestle chocolate chip cookie recipe substituting hemp hearts for the walnuts.)