On https://foursquare.com/manage/requests, how can I accept all friend requests at once on Foursquare? It is tedious to do it one by one:
No, there is not a way. However, if you are a celebrity or other popular person (think Twitter verified), Foursquare can convert your profile to a celebrity account, where the default friend add function is to follow, rather than add friend. Source: I am a Foursquare Superuser 3 and have asked the staff about this.