There are lots of competitors in this space: http://timetomeet.info http://timetomeet.info, http://www.needtomeet.com http://www.needtomeet.com, http://www.conv

There are lots of competitors in this space: http://timetomeet.info http://timetomeet.info, http://www.needtomeet.com http://www.needtomeet.com, http://www.convoko.com http://www.convoko.com, plus the ones already mentioned. The "meeting times" apps are becoming as numerous as project management apps and URL shorteners.