Root your Vibrant
***This will work on the T-Mobile US branded Vibrant and generic Galaxy S models***
***IMPORTANT: YOU PERFORM THIS AT YOUR OWN RISK, THIS MAY VOID YOUR WARRANTY, I NOR ANYONE ELSE IS RESPONSIBLE IF YOU BRICK YOUR DEVICE.***
***UPDATE: Now you can do this without ADB installed!
The following method should be relatively care-free but there is always a risk with activities like rooting a device or flashing a new firmware.
1. Download the attached zip and rename to: update.zip
2. On your device, navigate to Settings > Applications > USB settings
and select Mass storage
3. Plug your device into your computer, select mount USB from your device's pull-down window
4. Copy the update.zip to the INTERNAL SD memory (~14gb on this drive, not the one w/ Avatar if you've still got the 2gb SD card in)
5. Turn your phone off.
6. Hold down volume up and volume down while powering on the phone, this should get you to a recovery menu, you may have to try this a few times.
7. In Recovery menu select 'Reinstall Packages' (use vol_down then power to select)
Phone will reboot
and you have
2. busybox (/system/xbin/busybox)
Original credit goes to LeshaK at Samdroid, I modified the script within update.zip to work on the Vibrant.
Other credits to the fine folks in this thread that noted the vol up+down recovery menu.
I would link to the Samdroid forum but I can't...but check Samdroid > i9000 Development forum for the original post.