install android 2.2 froyo on samsung galaxy

Update: Android 2.3.3 Gingerbread is now available for the Samsung Galaxy S. Check out the installation guide below.
Guide Updated: Install Android 2.3.3 Gingerbread on Samsung Galaxy S
Updated: How to Install Android 2.3 Gingerbread on Samsung Galaxy S
Samsung has started rolling out the official Android 2.2 Froyo upgrade for the Galaxy S. You can install it using Samsung Kies.
Installing Android 2.2 on Samsung Galaxy S using Samsung Kies – Official Update

1. Download Samsung Kies and install it on your PC.
2. Connect your Galaxy S to your PC.
3. Select your phone and upgrade your firmware to Android 2.2 Froyo.
If the update is not available for your region, then use this tutorial.
How To Install Android 2.2 Froyo on your Samsung Galaxy S
How to Upgrade Samsung Galaxy S to Android 2.2 Froyo
The latest Android 2.2 Froyo ROM for the Samsung Galaxy S is I9000XXJP2.
Also check out this guide: How to Root Samsung Galaxy S
To upgrade your Samsung Galaxy S to Android 2.2 Froyo, you need to download these files
Odin 3 v1.0
S1_ODIN_20100512.pit
i9000XXJP2 Firmware (password: samsung-firmwares.com)
How to Install/Upgrade To Android 2.2 Froyo on Samsung Galaxy S: Instructions
1. Remove the battery, SIM card and MicroSD card from your phone and reinsert the battery.
2. Hold down the Home + Volume Down buttons and press the Power On button.
3. You should now see a download screen
4. Open Odin 3 v1.0
5. Click on the PIT button and load the “s1_odin_20100512.pit” file
6. Click on the PDA button and load the “I9000XXJP2-REV03-PDA-CL464213.tar” inside the I9000XXJP2 RAR file.
7. Click on the PHONE button and load the “MODEM_I9000XXJP2.tar”inside the I9000XXJP2 RAR file.
8. Click on the CSC button and load the “GT-I9000-CSC-MULTI-OXAJP2.tar”inside the I9000XXJP2 RAR file.
9. Click on the “Re-Partition” checkbox
10. Connect your Galaxy S to your PC with the USB cable and set USB Debugging On (System > Applications > Development > USB Debugging.)
11. Click on the Start button in Odin and your Galaxy S will be upgraded to Android 2.2 Froyo.

Note: If you have any problem with the method detailed above, you can try out this new guide – Install Android 2.2 Froyo on Samsung Galaxy S.