title: GPS coordinates: 1km square around a point
body: <p>I was hoping someone out there could provide me with an equation to calculate a 1km square (X from a.aaa to b.bbb, Y from c.ccc to c.ccc) around a given point, say <code>lat = 53.38292839</code> and <code>lon = -6.1843984</code>? I'll also need 2km, 5km and 10km squares around a point.</p>
  
  <p>I've tried googling around to no avail... It's late at night and was hoping someone might have quick fix handy before I delve into the trigonometry...</p>
  
  <p>I'll be running all this in Javascript, although any language is fine.</p>