Air travel is never dull

5:25am Get up. Shower. Have a quick bite to eat.
6:05am Leave the house with Wolfram and Lamia heading to SFO
7:00am Arrive at SFO rental car facility
7:15am Rental car returned, waiting for Airtrain
7:22am Arrived at Terminal 3.
7:35am Cleared security (long lines, but they were moving fast)
7:36am The monitor says "UA172 Boston 8:25 DELAYED"
7:38am Checked online at mobile.united.com. No delay posted. WTF?
7:45am Got coffee, a joghurt/muesli thing, and a chocolate crosissant at Peet's Coffee.
7:46am Coffee is GOOD!
7:52am Pick up a copy of Freakonomics.
7:55am Arrive at Gate 90 just in time for scheduling boarding.
7:56am "The aircraft is still in the maintenance bay. We don't know yet when it will be at the gate."
8:00am "We've been advised that the aircraft is ready. We are planning for a 9:00am departure."
8:30am Boarding begins. The gate attendants are super-efficient, and everyone co-operates. Great!
8:45am At my seat. Hmmm. No audio program yet. Video monitors are still dark. Strange. Engines off?
8:50am "This is the captain speaking, my 1st officer found a slightly bent blade in one of the engines while doing the walk-around. Maintenance is looking at it."
8:57am "This is the cabin attendant: This aircraft is not operable. Everyone please get off and wait in the terminal area."
9:20am At gate 81, waiting for replacement airplane. New departure time 10:25am.

What the hell was maintenance doing that they didn't notice a bent blade in the engines? LAME!

I should have taken the 10:30am flight to Boston on Virgin Atlantic...

Update:
We did leave on time on the second try. It's funny to travel alone, sit in the cabin and know exactly who your seat neighbors are going to be, even though they haven't boarded yet. We touched down at BOS shortly after 6pm local time, i.e. only one hour late even though we left two hours late.

I really like United's "Flight Deck" channel where they relay the conversation between pilots and air traffic controllers. However, it got turned on only when we crossed 10,000 feet, along with the other entertainment programs, so I couldn't listen to the pre-take off conversations while taxiing. Then, as we crossed a really wide river  (probably the Mississippi River at the Iowa/Illinois state border), they turned it off for the remainder of the flight. I suspect the initial black-out is for safety reasons, so people don't have to evacuate with earphones in their ears (lame...). The blackout for the second half of the flight is probably due to some braindead security restriction flying in the North-East of the US. Sigh.