THis is just amazing to me.
The Apps are tied to your iTunes user account, so it makes no sense to me how they do it.
Furthermore, these Apps are cheap, I buy one whenever I want, and it doesn't hurt my wallet.
It's far easier and more rampant than you actually realize.
As has been said before, you need a jailbroken iPhone/iPod Touch. There's an illegal App store available to those units. Pirated versions of apps appear within a couple of days of the real version going on sale in the official App store.
Almost everything is available including the expensive Sat Nav programs.