Disclaimer: Someone could theoretically mashup the sex offender registry, Google Maps, and Club Penguin. And that, I'll grant, would be a worse social network than the ones below.

We hear there were actually two companies who chose to forgo this week's Demo conference and present at Jason Calacanis and Michael Arrington's TechCrunch40 conference instead. The startups in question? Media-sharing service Wixi has confirmed that they will not be presenting at Demo, and we hear that avatar…