Over the weekend, the SourceRuns Team, comprised of fourteen players, got together and finished Half-Life 2, from beginning to end, in 1:27:51.09. Which, as you'll see in the video above, is madness. It's also a new world record.
Apparently it took "over 600 days of hard work", which means they deserve the title they gave to the run, which is "Half-Life 2 Done With a High Magnitude of Velocity".
Those interested in the specifics of the run, the team's YouTube page has links to all their documentation, including the glitches they used to squeeze out a few seconds.