When Should I Visit by Dan Williams is an elegant beta website that mines Foursquare data to determine the least busy times to visit museums and other cultural institutions in London. Williams also mentions an added feature: the site can be use to avoid foursquare users. The site was built in 24 hours for Culture Hackday 2011.
When Should I Visit? finds the least busy time to visit the museums, galleries and theatres of London. It states the quietest day and provides a glanceable graph to judge the relative popularity of different days. The site is intended to show the data in the simplest possible way with no unnecessary detail.