I really like what I've seen so far with Trumba. There is one thing I cant figure out though. I'd like to be able to post events to my calendar, and then have users 'sign-up' for those events giving me feedback as to who is attending and what they would like to do during that event. Similar to a potluck where people will sign up to bring different things, is there a way they can do this within Trumba as well?