We told you to get ready to visit Twitter last month – did you listen?

If you did, you’re among the 2,000 folks registered to attend two days of fun in the San Francisco (overcast) sun, starting tonight with an OpenCoSF kickoff reception.

If you didn’t, OpenCoSF registration is now closed. You’ll want to watch this space for updates.

In case you forgot, OpenCoSF is part conference, part festival and features open houses at more than 75 innovative companies “from airbnb to Zynga, with scores in between.”

Tonight’s gathering is an invitation-only event featuring Twitter CEO Dick Costolo “in conversation with event co-founder John Battelle, as well as a panel discussion featuring noted investor and philanthropist Ron Conway, github founder Tom Preston-Werner, and Silicon Valley Bank managing director Carrie Walsh. San Francisco Mayor Ed Lee will give opening remarks at 5:15pm.”

The event is San Francisco’s inaugural Innovation Month celebration and there will likely be many more.

We’ll be live-tweeting from the events tonight and tomorrow, so stay tuned! Will we see you there?

(OpenCoSF image from openco.us)