Agreed Kass! In-jokes are one of the medium if the audiences are known to us. But if one has to speak in front of unknown, the idea about making fun of the speaker himself, would work more.
I remember one line that compelled me to laugh and that is “If it wasn’t for all of you here today, I would be alone”. Lines like these always create a lighter atmosphere in the event. We can also invite speakers who are best in the particular form of speaking like after dinner speakers, good comedians and celebrities. I am having a video of a successful event which can give you the insight about it