A bunch of handy mixins for SASS. Who ever thought vendor prefixes were a good idea, anyway?

css3-mixins.css.scss

// Border Radius
@mixin round($radius: 4px) {
  -moz-border-radius: $radius;
  -webkit-border-radius: $radius;
  border-radius: $radius;
}
// Box Shadow
@mixin shadow($shadow1: 0 0 4px #0A0A0A, $shadow2:false, $shadow3:false, $shadow4:false, $shadow5:false) {
 $params: $shadow1;
  @if $shadow2
    { $params: $shadow1, $shadow2; }
    @if $shadow3 != false
      { $params: $shadow1, $shadow2, $shadow3; }
      @if $shadow4 != false
        { $params: $shadow1, $shadow2, $shadow3, $shadow4; }
        @if $shadow5 != false
          { $params: $shadow1, $shadow2, $shadow3, $shadow4, $shadow5; }

  -webkit-box-shadow: $params;
  -moz-box-shadow: $params;
  -o-box-shadow: $params;
  -ms-box-shadow: $params;
  box-shadow: $params;
}

// Inset Box Shadow
@mixin inner-shadow($shadow1: 0 0 4px #0A0A0A, $shadow2:false, $shadow3:false, $shadow4:false, $shadow5:false) {
 $params: $shadow1;
  @if $shadow2
    { $params: inset $shadow1, inset $shadow2; }
    @if $shadow3 != false
      { $params: inset $shadow1, inset $shadow2, inset $shadow3; }
      @if $shadow4 != false
        { $params: inset $shadow1, inset $shadow2, inset $shadow3, inset $shadow4; }
        @if $shadow5 != false
          { $params: inset $shadow1, inset $shadow2, inset $shadow3, inset $shadow4, inset $shadow5; }

  -webkit-box-shadow: $params;
  -moz-box-shadow: $params;
  -o-box-shadow: $params;
  -ms-box-shadow: $params;
  box-shadow: $params;
}

// Rotate
@mixin rotate($degrees: 2deg) {
  -moz-transform: rotate($degrees);
  -webkit-transform: rotate($degrees);
  -o-transform: rotate($degrees);
  -ms-transform: rotate($degrees);
  transform: rotate($degrees);
}

// box-sizing: border-box
@mixin border-box-sizing {
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  -o-box-sizing: border-box;
  -ms-box-sizing: border-box;
  box-sizing: border-box;
}

@mixin back-size-cover {
  -moz-background-size: cover;
  -webkit-background-size: cover;
  -o-background-size: cover;
  -ms-background-size: cover;
  background-size: cover;
}

//text-shadow
@mixin text-shadow($shadow: 0 1px 0 rgba(0, 0, 0, .2)) {
  -moz-text-shadow: $shadow;
  -khtml-text-shadow: $shadow;
  text-shadow: $shadow;
}

@mixin transition($transition: all .5s ease){
  -webkit-transition: $transition;
  -moz-transition: $transition;
  -o-transition: $transition;
  -ms-transition: $transition;
  transition: $transition;
}

@mixin transition-timing($trans-timing: cubic-bezier(0.230, 1.000, 0.320, 1.000)){
  -webkit-transition-timing-function: $trans-timing;
  -moz-transition-timing-function: $trans-timing;
  -ms-transition-timing-function: $trans-timing;
   -o-transition-timing-function: $trans-timing;
      transition-timing-function: $trans-timing;
}

@mixin transform($transform: scale(1)){
  -webkit-transform: $transform;
  -moz-transform: $transform;
  -o-transform: $transform;
  -ms-transform: $transform;
  transform: $transform 
}

@mixin rotate($deg: 90deg){
  -webkit-transform: rotate($deg);
  -moz-transform: rotate($deg);
  -o-transform: rotate($deg);
  -ms-transform: rotate($deg);
  transform: rotate($deg);
}

@mixin opacity($opacity: .8){
  -moz-opacity: $opacity;
  -webkit-opacity: $opacity;
  -khtml-opacity: $opacity;
  opacity: $opacity;
}

@mixin pointer-none {
  -moz-pointer-events:none;
  -webkit-pointer-events:none;
  -o-pointer-events:none;
  -ms-pointer-events:none;
  pointer-events:none;
}

@mixin backface-hide {
  -webkit-backface-visibility:hidden;
  -moz-backface-visibility:hidden;
  -ms-backface-visibility:hidden;
  backface-visibility:hidden;
}

@mixin backface-show {
  -webkit-backface-visibility:show;
  -moz-backface-visibility:show;
  -ms-backface-visibility:show;
  backface-visibility:show;
}