Spotting the ISS

I glanced outside last night to check the cloud cover for testing the Inclinomter, and through a momentary clear spot, something caught my eye. Well actually, it more reached out and grabbed my eyeball. It was so bright and yet lasted far too long for an Iridium flare, and was travelling in the wrong direction, so I figured it had to be the ISS. I checked on HA this morning and it was indeed the ISS at mag -2.5. It was a shame that within 5 minutes the gap in the clouds had gone, -8 would have been really bright.