downloading right now...
hopefully this flashes stock captivate firmware?
UPDATE: just ran it on my captivate (which was actually flashed to vibrant firmware and rooted)
it really is one-click! very convenient. just plugged in my phone in download mode.
but IT REALLY DOES WORK i'm back onto my captivate stock firmware, though it did wipe user data.
i did lose root, but... yeah. no biggy.
VERY GOOD FIND