Taken from here.

The idea here is that you have to press play on the following videos (in vertical order) so that they all stream to you at the same time. You may need to adjust the volume on each respective network, though. Press play on the top (YouTube) video, then immediately press play on the second (Google Video), and then press play on the third (Revver). Bam, bam, bam – and you should see ‘em playing back simultaneously.

Be sure to scroll down enough to see all three, then press “play” on each one, from top to bottom, so they all play at the same time.

It made the Windows Secrets & LangaList “Wacky Web Week” list!