Along with many other FReepers on the live thread, I watched the countdown in the JPL Command Center. No live video from Mars, but a live feed from JPL.
Due to the long (13 miute) radio signal propagation times, all they could do was report status as the telemetry signals came in. If you were familiar of the landing sequence depicted in this graphic:
You could follow the landing sequence progress quite well.
As each stage of the complex sequence was reported back as successful, there was an outburst of applause. Occasionally, an animation of that stage was shown.
When the announcement, "We have wheels-down on Mars!" was made, the room erupted in cheers and all-around handshakes and hugs.
Then, shortly, the first small "thumbnail" image was received from the rover, showing the surface of Mars and one wheel on the surface. The photo in this thread is a larger, higher-resolution version of that same view.
The rest of the live feed was speeches and (well-deserved) self-congratulation. It was well worth staying up past midnight to watch...