I had the same experience last night. HRH and I went to wiew what was predicted as a failrly ordinary pass (Mag 1.5) . 21:10:47 10 W 21:13:15 26 SSW 21:15:45 10 SE. Around a quarter of the way accross the sky the ISS flared I couldn't estimate the brightness but IMO it was brighter than the full moon. Venus at maximum mag is around -4 and in comparison to my recollection of Venus it was like having car headlights shine in your eyes. I'll be keeping an eye on Heavens Above for similar tracks and times after sunset to see if I can spot it again. As the others have said it is an awesome sight.
