Unlike many of my friends and colleagues I wasn't able to make it to Austin, Texas for this year's SXSW interactive, the four-day technology conference and festival that is currently firing the imagination of the technology world.

So I wasn't in the ballroom when the keynote address by Facebook founder Mark Zuckerberg went awry under the less-than-forensic questioning of technology journalist Sarah Lacy.

I didn't see the crowd start to get restless and heckle Zuckerberg about the deeply-unpopular Beacon advertising system, or get a chance to grab the microphone and ask questions when Lacy threw the conversation open to the floor.