This little mixin handles everything necessary to get a 'sticky' footer. Simply pass in the selectors for the DOM elements as described below.

stickyfeet.less

.force-height(@height: 100%) {
  height: @height;
  min-height: @height;
}

.apply(@selector: ~'', @contents){
  @{selector}{
	@contents();
  }
}

.sticky-footer(@wrap:~'#wrap',
				@content-wrap:~'#content-wrap',
				@footer-push:~'#footer-push',
				@footer-wrap:~'#footer-wrap',
				@height: 100px, @buffer: 25px) {

  	@wrap-rules:{
		.force-height();
  	};

  	@content-wrap-rules:{
  		min-height: 100%;
  		height: auto !important;
  		margin-bottom: -@height;
	};

  	@footer-push-rules:{
  		.force-height(@height);
	};

  	@footer-wrap-rules:{
  		padding-top: @buffer;
		margin-top: @buffer;
  		.force-height(@height - @buffer);
	};


	.apply(@wrap,@wrap-rules);
	.apply(@content-wrap, @content-wrap-rules);
	.apply(@footer-push, @footer-push-rules);
	.apply(@footer-wrap, @footer-wrap-rules);
}

<div id='wrap'>

     <div id='content-wrap'>

        <div id='header-wrap'></div>

        <div id='body-wrap'></div>

        <div id='footer-push'></div>

    </div>

    <div id='footer-wrap'></div>

 </div>