estimated iPhone 4 availablity without preorder?

[PecanEater]

What's the estimate (based on previous iphone/ipad releases) for how long after June 24 will I have to wait in order to simply walk in to an Apple store to by an iPhone4?

 

[Ferris23]

My guess is the first 3-4 days you will be able to get a phone albeit with a bit of a wait, then possibly a week of scarcity, then the following week a replenishment of stock with a similar pattern for the following 2 weeks.