Android 2.2(Froyo)

Android 2.2 called as the Frozen Yogurt or Froyo based on the linux kernel 2.6.32 was released on 20th May 2010.
The new features of this edition was

New home screen tips widget assists users on how to customize the five home screen available for you. The Phone, applications launcher and the Browser now have dedicated shortcuts on the home screen, making it easy to access from any of the home screen panels.

The security was improved with the addition of numeric pin or alphanumeric passwords to unlock the device. Exchange administrators can enforce password policy across devices. The Exchange administrators can remotely wipe or reset the device to factory settings in case the phone is lost or stolen. Exchange calendars are supported. Also you just need to know the username and password to easily setup and sync an exchange account. Google address lists lookup is available so users can auto complete recipient names from the directory.

Gallery allows you to peek into picture stacks using zoom gesture. The camera onscreen buttons provide easy access to a new UI for controling zoom, flash, white balance, geo-tagging, focus and exposure. Camcorder also provides an easy way to set video size/quality for MMS and YouTube.
Also LED flash was enabled for the camrecorder, enabling videos to be shot at night or low light.

Your device could function as a wifi hotspot for 3G connection with the number of maximum connections running to 8.

Multi-lingual users can add multiple languages to the keyboard and switch between multiple Latin-based input languages by swiping across the space bar. This changes the keys as well as the auto-suggest dictionary.

Improved performance of the browser available with the V8 engine which enables the loading of javascript faster.]

Dalvik Performance Boost: 2x-5x performance speedup for CPU-heavy code over Android 2.1 with Dalvik JIT.

Improved memory reclaim by up to 20x, which results in faster app switching and smoother performance on memory-constrained devices.

Bluetooth
Voice dialing over Bluetooth
Ability to share contacts with other phones
Support for Bluetooth enabled car and desk docks
Improved compatibility matrix with car kits and headsets

HIGHMEM support for RAM >256MB