iOS 4, iPhone 4, and iTunes 9.2 Compatible.
Feeling the Jailbreak Blues? Why not get access to your file system and access files directly from your finder while you wait for that unnamed Jailbreak Tool. Phone Disk, from the creators of iPhone Explorer (Macropant), will allow you to mount an iPad, iPhone (4), and iPod Touch to USB disk mode on a Mac. Phone Disk runs in the system tray of your Mac. Once mounted you can use it just like any other USB Drive.
The application supports multiple devices, and gives you access to things like preview, open, edit, etc. Right now Phone Disk is Free, but it won't be forever. Sept 1, 2010, Phone Disk will include a minimal fee, but in the mean time, you can grab a free license and activate it now before this expires.
Download Phone Disk for Mac
If you're a Windows user and need a similar program, iPhone Explorer comes pretty close to Phone Disk for Mac.
Thanks to iLaw-one for the tip