A Target employee posted a list he claims is the number of Wii launch units at Target stores. The post reads like a ridiculously long list of random numbers. The only two numbers you'll care about is the first one and the second to last number. The first tells you the store number, which can easily be found by calling your local Target, and the second to last number is how many units they will receive.
If you aren't into getting all DaVinci Code, there is also the option of using a "Wii Searching Doohickey." It says you can search by area code, you can also try putting in the closest major city, either way it's wonky -- try the DaVinci Code route.
[Thanks to all those that sent this in]