Apple has formally unveiled iPhone 4.0 , the next upgrade for the iPhone . There were already rumors going on regarding the iPhone 4.0 which would be emphasize on multitasking for the first time, users can now double tap the home button and use the multi-tasking feature allowing third party applications to run simultaneously and used from the list .
Extensions of multi-tasking will allow users to interact with background applications like Pandora , Skype , maps , and other third party apps which make use of GPS .
The firmware would be consisting over 100 new features in total such as 
- Geo-tagging
- Gifting Apps
- Spell checker
- 5x digital zoom
- Tap to focus for video
- Separate background wallpaper
- Improved Mail app with unified inbox and message threads also comprising connection to multiple accounts and attachments
- An important interface change is the ability to create homescreen folders by dragging icons
And many more features will be added limiting exclusivity to iPhone 3GS and Third-gen touch. The iPhone and iPod are going to be released in the summer , but iPad may not come up this summer with the 4.0 .
A developer preview of firmware is made available , with access to more than 1,500 new API’s , now iPhone developers have much more to deal with and the new API’s are really going to change the rules of iPhoning .
