open a foursquare venue from a browser in the iOS app (original src + Closure Compiled bookmarklet)

open-in-4sq.bookmarklet.js

javascript:(function(){var a=document.location.pathname.split("/"),b=a.length-1;if(!(0>=b)&&"v"==a["touch"==a[1]?2:1])document.location="foursquare://venue/"+a[b];})()

open-in-4sq.js

(function() {
  // Open foursquare Venue in iOS App

  var components = document.location.pathname.split("/");
  var last = components.length - 1;

  if (last <= 0) return;
  var touch = components[1] == "touch";
  var checkForV = touch ? 2 : 1;
  var onVenue = components[checkForV] == "v";
  if (!onVenue) return;

  // Get venue ID
  var venueID = components[last];
  document.location = "foursquare://venue/"+venueID;
})();