   Math.round((Math.pow(10, length + 1) - Math.random() * Math.pow(10, length)))
     .toString(10)
     .slice(1)
+
+
+# TODO: if this feature is popular, copy these images into tawk rather than
+# serving from Wikimedia directly.
+avatar_urls = [
+  'https://upload.wikimedia.org/wikipedia/commons/thumb/e/e9/Black_Man_Working_at_his_Laptop_on_the_Couch_Cartoon_Vector.svg/2880px-Black_Man_Working_at_his_Laptop_on_the_Couch_Cartoon_Vector.svg.png',
+  'https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Corporate_Woman_Working_at_her_Desk.svg/2880px-Corporate_Woman_Working_at_her_Desk.svg.png',
+  'https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/A_Humble_Cartoon_Businessman.svg/1920px-A_Humble_Cartoon_Businessman.svg.png',
+  'https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/A_Confident_Cartoon_Businesswoman.svg/1920px-A_Confident_Cartoon_Businesswoman.svg.png',
+  'https://upload.wikimedia.org/wikipedia/commons/thumb/4/48/Cute_Santa_Claus_Character_Giving_The_Thumbs_Up.svg/1920px-Cute_Santa_Claus_Character_Giving_The_Thumbs_Up.svg.png',
+  'https://upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Batman_Clipart.svg/660px-Batman_Clipart.svg.png',
+]
+next_avatar_url = (current_url) ->
+  current_index = avatar_urls.indexOf(current_url)
+  if current_index == -1
+    index = Math.floor(Math.random() * avatar_urls.length)
+  else:
+    # Cycle through avatar urls in order
+    index = (current_index + 1) % avatar_urls.length
+
+  return avatar_urls[index]
 
 should_hear_fully = (person, me) ->
   me.group in [person.group, person.mouseover] or

      borderRadius: 4
    @props.children


VIDEO_ICON = (props) ->
  SVG

              opacity: .9999 # http://stackoverflow.com/questions/5736503
              borderRadius: 1 # TODO: why is this necessary? https://github.com/invisible-college/tawk.space/issues/40
      else
        NO_VIDEO_AVATAR
          person: person
          height: height
      if person.audio
        DIV
          style:
