How about a conference called "In Retrospect" in which presenters revisit talks they've given years prior -- and describe how their thinking has evolved since?

@VodafoneAU_Help wait, so you have to opt out of being harassed by Vodafone now? Great way to make me feel like a valued customer.

@VodafoneAU_Help so were these sales calls from a third party, or from you directly?

@VodafoneAU_Help I told the guy I wasn't interested after 5 calls yesterday. Why would you set a spammer on me? Do you want me to leave?

@VodafoneAU_Help done. I look forward to you explaining in detail what terrible business process lead to this situation.

@VodafoneAU_Help so I emailed you, but you didn't reply.

@tristangoode I am now a cloud of irrelevance, and loving it.

@tristangoode Self (Parody) we'd be nice to you...

Linuxconf now streaming at timvideos.us (I'm told) so you can watch #lca2016 with me