Until iPhone 2.0 software is released in June, if you want to add third-party software to your iPhone, you first need to jailbreak it. Jailbreaking, however, is only the first step. The next step is to actually install your choice of software. For this task, hackers have standardized on an iPhone application called, appropriately enough, "Installer." This program downloads software directly to your iPhone, much as Apple's App Store promises to do. If you decide to jailbreak your iPhone, you'll need to get comfortable with this Installer.