Joined: Dec. 2007
Now that I've sidetracked another thread, next time you see a streak in the sky, go here: http://www.heavens-above.com/
This site will provide star maps showing the paths of satellites across the sky. After putting in your location, click on ISS for a list of visible passes of the International Space Boondoggle (enough money to have built the Superconducting Supercollider and what do we have to show for it?), complete with star maps.
But since you mentioned Iridiums, also click on Iridium Flares. Each Iridium satellite has some flat panel antennas that are as reflective as mirrors. When one of those antennas reflects the sun directly to you, they will get unDarwinly bright. I've got one coming over tonight that's magnitude -8, for instance. The brightest stars in the sky are about mag 0, Venus is mag -4 and mag -8 probably throws shadows. I've always been too busy looking up to check.
Heavens above will give you altitude, direction and time to watch for them. They go from invisible to the naked eye to blindingly bright and then back to barely visible in about ten or fifteen seconds, and it's a very intense ten or fifteen seconds!
P.S. Mrs. O'Leary, all of the above is based on science, so you can ignore it.