firebug.sheet

  <command> <shift> L  => brings up the firebug console
  
  Logging:
    console.log("message" [,objects])
    console.debug("message" [,objects])
    console.info("message" [,objects])
    console.warn("message" [,objects])
    console.error("message" [,objects])
  
  Assertions:
    console.assert(a, "message" [,objects])
    console.assertEquals(a, b, "message" [,objects])
    console.assertNotEquals(a, b, "message" [,objects])
    console.assertGreater(a, b, "message" [,objects])
    console.assertNotGreater(a, b, "message" [,objects])
    console.assertLess(a, b, "message" [,objects])
    console.assertNotLess(a, b, "message" [,objects])
    console.assertContains(a, b, "message" [,objects])
    console.assertNotContains(a, b, "message" [,objects])
    console.assertTrue(a, "message" [,objects])
    console.assertFalse(a, "message" [,objects])
    console.assertNull(a, "message" [,objects])
    console.assertNotNull(a, "message" [,objects])
    console.assertUndefined(a, "message" [,objects])
    console.assertNotUndefined(a, "message" [,objects])
    console.assertInstanceOf(a, b, "message" [,objects])
    console.assertNotInstanceOf(a, b, "message" [,objects])
    console.assertTypeOf(a, b, "message" [,objects])
    console.assertNotTypeOf(a, b, "message" [,objects])
  
  Measurement:
    console.trace()
    console.time("name")
    console.timeEnd("name")
    console.count("name")
  
  String Formatting:
    %s            string
    %d,%i,%l,%f   number
    %o            link to inspector
    %1.o          interactive table of properties
    %.o           array of property names
    %x            XML
    %N.x          XML with N levels expanded
  
  Command Line:
    $("id")          document.getElementById()
    $$("css")        array of elements matching css selector
    $x("xpath")      array of elements matching xpath
    $0               last inspected object
    $1               next-to-last inspected object
    $n(N)            N-th from last inspected object
    inspect(object)  display object in inspector
    dir(object)      array of property names for object
    clear()          clear console
  
  http://www.joehewitt.com/software/firebug/