Hey Simon. re: friction, I built a little service about a month ago that creates events via email — www.thad.cc

You just need to cc the address in an email and it sends invites to all of the people in the email list. I used it for an event of about ~30 and most people added their RSVP. It has chat too, but that wasn't as successful. Email is obviously not the 'coolest', but this approach at least reduces friction. I spent about a month thinking about / building this and would be happy to chat.

Edit: kinda funny we both chose pink :)