iPhone OS 3.0 requires iTunes 8.2 so you will have to first updrade your iTunes to 8.2 to download the latest iPhone OS.

Following is the list of Top Ten new Features of iPhone OS 3.0

1) Cut, Copy & Paste
Quickly and easily cut, copy, and paste text from application to application. Select entire blocks of web text with a tap. Copy and paste images from the web, too.

2) Landscape Keyboard
Want more room to type? Rotate iPhone to landscape to use a larger keyboard in Mail, Messages, Notes, and Safari.

3) MMS
Send MMS messages and include photos, audio, and contact info.
Even tap to snap a picture right inside Messages.
MMS is not supported on first-generation iPhone (2G). Sending video via MMS is not supported on iPhone 3G, since, the camera can’t capture video.

4) Spotlight Search (Universal Search Feature)

Find what you’re looking for across your iPhone, all from one place. Spotlight searches all of your contacts, email, calendars, and notes, as well as everything in your iPod.

5) Voice Memos

Capture a memo, a meeting, or any audio recording on the go. Voice Memos works with the built-in iPhone microphone or with the mic on your headset.

6) Movies and TV Shows direct download
In iPhone OS 3.0, users will be able to rent and download movies, tv shows directly onto their iPhones.
Apple already allows users to download songs, podcasts and iPhone apps over the air using iPhone’s data connection if the file size is less than 10 MB, if the file size is more than 10 MB, users will have to download it over Wi-Fi. Thus, it is anyone’s guess that Apple is indirectly stating that this feature will only work over Wi-Fi.

7) Tethering Capability

iPhone OS 3.0 will also bring the ability to tether the iPhone to feed a data connection to your computer and surf the internet.However it will depend on carriers to add tethering support on their networks.

Find My iPhone and wipe feature
iPhone OS 3.0 will include a feature called ‘Find my iPhone’. The service will obtain iPhone’s location and make it available to MobileMe user on request if the unit is lost or stolen.
The users will be able to protect their privacy by sending remote wipe instructions, which will wipe off all data from lost or stolen iPhones.

9)Push Notification Service
One of the most anticipated features of iPhone OS 3.0 and Apple’s solution or workaround for the ability to run third party iPhone apps in the background especially for applications like Instant Messenger, Facebook etc.

10)New Languages
iPhone improves it multi-lingual capabilities by supporting 30 languages and more than 40 keyboard layouts.

Apple’s unveiled a new iPhone today at WWDC, the iPhone 3G S — the “S” stands for speed.

Most powerful iPhone yet,  iPhone 3GS features video recording, Voice Control, up to 32GB of storage, and more.

Although it looks almost exactly like the 3G, it’s much, much faster — some tasks are almost five times faster.

Contract price is set at $199 for 16GB and $299 for 32 GB when it goes for sale and current iPhone 3G will remain available at new price of $99.