Multitasking: iPhone users will finally be able to run iPhone apps in the background. To achieve this Apple will be offering developers seven multitasking services, which will allow their iPhone app to run in the background while preserving performance and battery life.
Folders: Users will be able to organize iPhone apps on their iPhone home screen [...]

iPhone4 is here to change everything again. Find below then features that will keep it different then any other phone.
FaceTime: iPhone 4 comes with two cameras, a front facing camera in addition to a camera at the back.
The front facing camera will allow iPhone 4 users to make and receive video calls. You can switch [...]

The new iPhone 3.0 update has 100 new features, including the following:

Browse and download movies, TV shows and audiobooks from the iTunes Store**
Stereo Bluetooth*
Shake to shuffle
New Voice Memos application*
Cut, Copy & Paste with shake to undo
Landscape keyboard in key applications
Added search feature in Music, Videos, Mail, Calendar [...]

redsn0w is an easy to use, multi-platform, multi-device jailbreaking and unlocking (iPhone 2G only) tool for the iPhone 2G (original iPhone), the iPhone 3G (but not the 3GS) and also the iPod touch (first and second generation).
Currently it is available for Windows and Mac OS X (there are some issues using redsn0w with OS X [...]

This is the low down on the tools for use with the 3.0 firmware from Apple, read the whole post in full before attempting anything. Because of some bugs and unexpected changes this will be a multipart release, starting with the release of PwnageTool for Mac OS X. QuickPwn for Mac OS X and Windows [...]

Apple has released iPhone OS 3.0 (Build 7A341) just as they had announced at WWDC
2009 Keynote address. Here are some of the features to look out for in iPhone
OS 3.0:
Cut, Copy & Paste: Users will be able to cut, copy and
paste text. The blocks of text could be selected from application
and web by simply taping [...]

The Fastest iPhone Ever
The first thing you’ll notice about iPhone 3G S is how quickly you can launch applications. Web pages render in a fraction of the time, and you can view email attachments faster. Improved performance and updated 3D graphics
deliver an incredible gaming experience, too. In fact, everything you do on iPhone 3G S [...]

One of the long-awaited features the iPhone 3.0 software update brings to the iPhone and iPod touch–specifically, the iPhone 3G and 3G S and the second-generation iPod touch–is Bluetooth’s Advanced Audio Distribution Profile (A2DP). A2DP lets you stream stereo audio to other devices over Bluetooth; for example, so you can listen to music and other [...]

The free iPhone OS 3.0 Software Update includes some great new features, as
well as all the features from previous updates. iPhone OS 3.0 also lets you
run the next generation of iPhone apps, like peer-to-peer games1 and more. If
you’ve never updated before, now is the perfect time.
Cut, Copy & Paste: Quickly and easily cut, copy, and [...]