How would you like to be able to mount a non-jailbroken iOS device as a disk on your Mac or PC? And what if this capability was (for a limited time) free? My guess is that a lot of you would take someone up on an offer like this.
Developer Macroplant has come up with a solution that runs on a Mac with OS X 10.5 or 10.6, or on a PC with Windows XP/Vista/7, that allows you to view the contents of your iPhone, iPod touch or iPad. Phone Disk lets you open, copy and save files directly on the device, and you can mount multiple devices simultaneously. If you're a Mac user, you see the iOS file system in the Finder, while Windows users can view it in Windows Explorer. The app runs in the system tray in Windows or the menu bar in Mac OS X, so it's out of the way, but available when you need it.
Note that Phone Disk will not give you "real" root access to your iOS device -- the program allows you to access media files (photos, music, and even apps), but system-level access still requires a jailbreak. Still, this is more access than non-jailbreakers can get otherwise -- if you know where to look, you can even pull soundtrack files out of the apps installed on your iPhone.
Through December 1st, 2010, the developer is giving away Phone Disk for free. You just need to download and then unlock the software with the registration code available here.