CoffeeScript

HTML

<script src="https://github.com/jashkenas/coffee-script/raw/master/extras/coffee-script.js"></script>
<center>
  <input id="tag"/> <br/>
  <div id="msg"></div>
  <img id="result" width="300"/>
</center>

CoffeeScript

flickr = 'http://api.flickr.com/services/rest/?format=json&nojsoncallback=1&api_key=256663858aa10e52a838a58b7866d858'

showPhoto = (p) ->
  $('#result').attr 'src', "http://farm#{p.farm}.staticflickr.com/#{p.server}/#{p.id}_#{p.secret}.jpg"
  
searchTag = (tag) ->
  $.get "#{flickr}&method=flickr.photos.search&sort=random&per_page=10&tags=#{tag}", (results) ->
    n = Math.floor Math.random() * (results?.photos?.photo.length-1)
    showPhoto results?.photos?.photo[n]
        
$('#tag').keydown ->
  setTimeout (-> searchTag $('#tag').val()), 10