PlayStation 3 preorders will be taken tomorrow at Gamestop and EB Stores. I’m fairly certain that the preorder window is going to be extremely short, so you may want to be there when the store opens (check with you local store to see their store hours). You’ll be required to put down a $100 deposit on the console, so you’ve got yourself about 14 hours to free up the cash.
Good luck!
Note: According to Gamestop, each store will receive either 8 or 16 units with two going to employees. So you either have to be within the first 6 or 14 on the list if you want to get one depending on your store’s allocation.