United we fly?

Thanks to a combination of my own stupidity and the stupidity of United Airlines' policies, I had quite an adventure trying to fly home from San Francisco to Boston yesterday. Here's how it went down:

1. I skipped my usual practice of checking the flight status and time the night before my flight because my 24-hour wireless Internet access that I'd paid for had expired.
2. Believing, as I had all week, that my flight left SFO at 10-something in the morning, I checked out at 7:45. Before getting a cab, I decided to use the free wireless in the lobby to check the flight status.
3. Oops! The flight was 8:31, not 10:00 or later, as I'd thought. Uh-oh.
4. I hopped in a cab and arrived at SFO at 8:10, 21 minutes before flight time. And the departures board said the flight was "delayed," though it didn't specify how long.
5. I tried to check in (quickly, of course), but I learned that I was too late. Apparently you can't check in less than 30 minutes before flight time, even if the plane hasn't started boarding yet.
6. I had to call the Continental reservations line to rebook myself onto a 1:00 flight. No chance of standby on the 11:30 flight, because it was way oversold. After confirming a seat for me at 1:00, the reservations agent told me that I should call back after 9:00, because then the change fee for reticketing me will only cost $50, not $100, because the price goes down within four hours of flight time.
7. I ate some breakfast and then called back at 9:05 to reticket, which went fine. I was now out $50 and had a confirmed seat on the 1:00 flight.
8. Around 9:20 or 9:25, I decided to go through security so that I could take advantage of the stores and restaurants within the secured area of the terminal.
9. At 9:30, I got through security and checked the departures board. The 8:31 flight that I'd "missed" was now listed as departing at 10:00 (ironically, the time I'd originally thought it was supposed to leave).
10. Since I had nothing better to do, I walked over to the gate where that flight was departing, and I saw that it was just boarding. I asked the gate agent if there was any way to fly standby, since I was booked on a later flight. Amazingly, he said, "yes."
11. Five minutes later, I had a boarding pass for my original flight. Shortly after 10:00, I took off. Depending on your perspective, I was either an hour and a half late, right on time, or three hours ahead of schedule!

Now, my most important lesson from this experience is that it's important to double-check to make sure you know your departure time. However, I'm also convinced that United's policies are out of whack. Why lock out check-in before the flight starts to board? There's clearly enough time to check in, get through security, and get to the plane if boarding hasn't even begun yet. And why is it cheaper for me to change my ticket at the last minute than farther ahead, especially if both are on the day of the flight? And, just for good measure, why is the 11:30 flight heavily oversold but the 8:31 flight swimming in extra seats? Shouldn't United contact some of its 11:30 flight customers to see if they want to switch to the earlier flight?

Oh, well. At least I got home safely and even without sitting around the airport for several hours. I'm still a little bitter about the $50, though.