1. Make a post (public, friendslocked, filtered...whatever you're comfortable with) to your LJ. The post should contain your list of 10 holiday wishes. The wishes can be anything at all, from simple and fandom-related ("I'd love a Snape/Hermione icon that's just for me.") to medium ("I wish for _____ on DVD.") to really big ("All I want for Christmas is a new car/computer/house/TV.") The important thing is, make sure these wishes are things you really, truly want.
Also, make sure you post some version of these guidelines in your LJ, so that the holiday joy* will spread.
2. Surf around your friendslist (or friendsfriends, or just random journals) to see who has posted their list. And now here's the important part:
If you see a wish you can grant, and it's in your heart to do so, make someone's wish come true. Sometimes someone's trash is another's treasure, and if you have a leather jacket you don't want or a gift certificate you won't use—or even know where you could get someone's dream purebred Basset Hound for free—do it.
You needn't spend money on these wishes unless you want to. The point isn't to put people out. There are no rules with this project, no guarantees, and no strings attached. Give and you might receive. And you'll have the joy of knowing you made someone's holiday special.
1: Peace on Earth
2: Goodwill in all humans
3: See number 1
4: See number 3
5: See number 4
6: See number 5
7: See number 6
8: See number 7
9: A bottle of Jim Beam
10: To see Dubya beheaded and his head kicked down the road like a soccer ball
Nicked from loads people...
I might be a tad cynical in guessing that I'll only get one of my wishes fulfilled...