title: Textarea lags after registering `keydown` events using Javascript
body: <p>How does one go about attaching a bunch of code to an <code>onkeydown</code> event, but keep entering text into a <code>textarea</code> fast and crisp? Anything more than a couple of IF statements seems to slow it down quite considerably.</p>
  
  <p><strong>EDIT</strong>: I should add (can't believe I forgot!) that this doesn't affect desktop browsers. It's mainly an issue with iPhone Safari. Other mobile browsers might be affected as well, but we're focusing on iPhone Safari since it executes JS the best (AFAIK)</p>