Turns out 11 month olds can throw an iPhone pretty far.
My daughter picked up my iPhone 3gs when I was out of the room and my wife had her in her arms. When i came back, it was cracked; after 2 years and 5 months of babying it, it was cracked.
Irony: I had ordered the 4s and got the email telling me it was arriving in the store the next day, so i went on facebook and told my friend to whom i promised the phone that she'd get it soon... 30 minutes after the email, it became projectile. Feeling like an idiot, i had to write her back and let her know what had happened...
It was beautifully simple. I watched a few videos on how the process would go (including yours), so i was pretty much ready for what was coming. As soon as the package came in the mail, i got down to business and it went absolutely flawlessly.
Yes... my only improvement on your guide would be to advise people to put a piece of packaging tape on top of the cracked panel to keep it in place and avoid any potentially dangerous pieces of frayed glass. It made the removal SO MUCH EASIER (I did it MID-process when i thought it would help)
NOTE: pics included are mid-process, after and the CAUSE!!!