Apple stores are selling iPhone 4s via website reservations on apple.com, with NO DEPOSIT REQUIRED. Be on the site at 9PM and reserve your phone for pickup in store the next day. Not all models are available every day, but it's still a better shot than "we're not sure when we will have our phone". They do go quickly so be sure to check out the site in advance to see where to go, and try to reserve right at 9.
If you don't have a local Apple store, go to your local Sprint store. Mine said they are filling orders every day with a 2-3 day turnaround from when the order is placed with a $50 deposit.
When you get your phone, go to Best Buy, cancel your pre-order, get your gift card refunded, and then refuse to give them your business in the future. There is nothing that Best Buy offers that we can't all get somewhere else, from a company that appreciates their customers and treats them accordingly.