At this year's F8, Mark Zuckerberg's keynote was opened by Andy Samberg doing a 5 minute impersonation of Zuck (or, as Samberg began calling his character, "The Zuck Dawg").
Turns out there's another funny example of a tech CEO opening with a look-a-like.
In 1999, Steve Jobs invited Noah Wylie, who had just played Jobs in The Pirates of Silicon Valley, to open up his Macworld Keynote. Ever the showman, Jobs does a bit better job of managing the stage than Zuckerberg did. But, the similarities are pretty entertaining.
The result for both was a pretty funny and eye catching way to open a keynote, a bit cheesy, but pretty enjoyable.