Those of you that need to flash back to the Samsung Vibrant stock ROM can do so with the following directions.  This works on phones that are updated to Froyo and need to be flashed back to gain root access as well as those who have bricked their Vibrant by messing around.

You will need drivers installed on the computer that you use to flash your Samsung Vibrant back to the stock rom.
You can get these drivers here: 32-bit Driver | 64-bit Driver

Instructions to flash Vibrant back to Stock:

1. Get your phone into Download mode by holding volume down and power.
2. Download Odin for Flashing (Download Link)
3. Open Odin
4. Extract and Load the 512.pit file (Download Link)
5. Extract and Load the Vibrant JFD Image (Download Link)
6. Don’t check anything else, “Auto Reboot” and “Reset Time” should be checked by default
7. Connect your phone to the Computer via USB
8. Hit “start”! be patient!

If you don’t see a progress bar after hitting start (after a minute) start over at step one.

Having Trouble with Download Mode:
If you are stuck on the PC and phone screen just hold both volume buttons and power at the same time. let the Vibrants screen come on and go back off and on the second time before the Vibrant comes back on let go of the power button while still holding the volume buttons. This should get you back to download mode.