Who else besides Apple typically offers Iphone preorders?
The carriers pre-sell and also have pre-order queues from years past. It's not been something that other retailers have offered as the quantities sent through distribution channels is largely taken by large corporate buyers looking for as many devices as possible so until production catches up with demand, your best bet might be to pre-order directly from Apple and have home delivery scheduled if you don't want to try your luck with the waiting in line game. (You can always go wait in line if you care, knowing your phone has been pre-ordered but the reverse hasn't been true once the initial allocation of pre-orders sells out.)