Said to be super fast, lag free, and marked Android 2.2.1 i9000XXJPU, this could very well be the Froyo build you’ve always wanted for your Galaxy S. This build fixes many issues complained about in Froyo for Galaxy S, punching lag right in the face as well as a list of other items. Delivered by none other than the friendly folks over at XDA Developers Forum.

Take a peek at just some of the things this leak adds to your now-happy phone, courtesy of course of XDA superstar kalpik and friends:

– 339MB free RAM because of reduced drivers footprint 
- improved UI speed 
- improved browser speed 
- reportedly improved GPS and video player 
- OTA (over-the-air) updates, however it is not known if this version will receive any. 
- ability to change lock screen wallpaper 
- swype version 2.9.51.13071 with the following languages: 
[spelling by XDA] US English, UK English, Nederlands, Francais, Deutsch, Italiano, Polski, Portugues, Espaniol, Türkce, and more (reportedly Ukrainian or Korean)

Speed and sweetness. Remember that this is a leaked and non-official firmware update that cannot be installed through Kies. Some people who’ve upgraded have reported backup/restore to sdcard function missing. If you know what you’re doing, feel free to upgrade. If you’re unfamiliar with what to do with files that allow you to root and add an unofficial build upgrade to your phone, probably just don’t do it.

Download Android 2.2.1 for Samsung Galaxy S i9000XXJPU

Download Root for Android 2.2.1 for Samsung Galaxy S i9000XXJPU

[Via XDA Developers]