On Apple’s page, the iPhone 4 still says 3 weeks for shipping for all new orders, and they’re not kidding. I placed an order this weekend, and the delivery estimate is July 30th. Ouch.
You won’t have much luck elsewhere. I called around, only to find everyone was sold out in my area. The only estimate I got was from AT&T, who said they expect more within the next 7-10 business days.
If you’d like an iPhone, it may be a good idea to order one now. At least then you’ll get one by the end of the month.