It is likely that Apple will release iOS4 for the iPhone today, perhaps around 10 PST. iTunes will update you automatically on the date listed in Summary. To proactively update your iPhone, in iTunes click on your iPhone (under Devices on left column). Then in Summary screen click "Check for Update".
The feature I am most looking for is folders. That will allow me to place icons for all my iPhone Apps on the iPhone . The other feature I look forward to, multi-tasking, will evolve in its usefulness overtime, as developers conform to iOS4 API.

Hal, If I am correct, 3Gs
Hal,
If I am correct, 3Gs owners get most of the benefits of IOS4 including multitasking.
3G owners get some of the new features without multitasking and 2G owners are not able to upgrade at all.
iOS4 now available for update.
Its official: iOS4 is available: plug in your phone and request the update using iTunes 9.2.
To create folders on your
To create folders on your iOS4 device: