This is the wrong place for capturing info like planned attendance. There are free services like meetup.com that I am a member of many groups that enables members to RSVP. It's a good service and provides many features. Perhaps creating a NBC group and adding everyone as members would work.
When you create a meeting within the group, everyone in the group will get notified and can RSVP with either "Maybe", "Yes" or "No". So you know where you stand. These updates get sent out via email.
An example of this is SyncNorwich - a technology group in Norwich:
http://www.meetup.com/syncnorwich/events/150047742/
It supports comments per meeting and photos to be uploaded and hosted on meetup. It is a better place than oople for this I think.
I work in the tech field @ Microsoft so use meetup a lot.
I'm finding most of the meets at NBC clash with Coastal and as I prefer to race on astroturf because it's clean and I have very little time to strip down and clean my car between race meetings, I tend to drive down to Ipswich and race there.
Simon