The iPhone-dev team has announced the availability of the latest tools for the iPhone, allowing even the most technically illiterate iUser to install unapproved applications.
The tools and techniques have been around for a while, but are now all bundled together into an easy-to-use package for Windows - a Mac version is under development. The latest tools don't replace the firmware on the iPhone, but rather remove the installation restrictions and install an application to manage the illegitimate apps the user is presumably wanting to run.
With iTunes now offering a range of Apple-approved apps, the motivation to hack one's iPhone is much reduced, so the process needs to be really easy if anyone is going to bother. There aren't a lot of applications that are only available from outside the Apple channel, but those wanting to run them are still obliged to make use of tools such as this.
The 3G iPhone still lacks a software unlocking process, though the dev team say they're working on it. This is taking a while, most likely because everyone with a 3G iPhone has been required to sign up to a contract, so not a lot of people are interested in unlocking their handset to use on another network.
No system is completely secure - the trick is to make breaking the security a pain, and the alternatives easy and cost-effective. This graphical toolkit makes breaking the security a lot less of a pain, but Apple has come a long way in making the alternatives painless too. ®