Unfortunately I can read very few Chinese characters, but I can speak it and perhaps that is enough for me to explain.
During Chinese New Year, you will oftenly see the Chinese character for 'Luck' (which is 'Fook' in Cantonese -- And no, it is not 'Fuck') turned upside down. The reason for that, is that the word 'upside down' means 'coming back' also. So if you put those facts together and arrange them into a sentence it would be: "Luck coming back to you." In other words, "Good Luck will come to you."
That's actually the second part of the story, the first part I am unclear and I've heard many variations which makes it even more unclear, so I won't try to explain, but I'm sure some people (not necessarily Chinese) will know of this, and should append to this node!
If you've been on google recently, you'll notice the inverted 'Luck' Chinese Character on the main pic.
Kung Hey Fat Choi!
...and Glory to You, and Your House!