So I'm not working on this but I'm working on software that might be the base for this? An Open Source collaborative wiki calendar http://ican.openacalendar.org

So I'm not working on this but I'm working on software that might be the base for this? An Open Source collaborative wiki calendar http://ican.openacalendar.org/ http://ican.openacalendar.org/ As others have said, data is the main problem. Sometimes it might be best to focus on a small area or niche. There are lots of sites like this but the ones that succeed generally seem to cover one area or niche (or both)?