[Gozar]

Это был не самый распространенный вариант, а теперь сюрприз, самый распространенный:

<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<script type="text/javascript">
(function( $ ){
	$.fn.correctLines = function( maxLine, moreText ) {

		var self = this[ 0 ], temp, classes, i, lineHeight;

		maxLine = ( temp = /^(?:.*\s)?fixline_([\d]+)(?:\s.*)?$/.exec( self.className ) ) && temp[1] || maxLine || 3;
		moreText = moreText || '...<br />';

		var clone = $( self ).clone( true ).
				css( {"height": "auto", "width": self.offsetWidth + "px"} ).html("W");

		clone.appendTo( document.body );

		lineHeight = this.css('line-height');

		if ( lineHeight == "normal" ) {
			lineHeight = clone[0].clientHeight;
		} else if ( ( lineHeight + '' ).indexOf("px") > 0 ) {
			lineHeight = parseInt( lineHeight );
		} else {
			lineHeight = parseInt( this.css('font-size') ) * parseFloat( lineHeight );
		}

		var height = lineHeight,
			width = self.offsetWidth,
			lines = 0,
			lastHeight = 0,
			startWord = 0,
			endWord = -1,
			txt = self.innerHTML.split(" "),
			part = [];

		clone.empty();

		for( i = 0; i < txt.length; i++ ) {

			clone[0].innerHTML += txt[ i ] + ' ';

			if ( clone[0].offsetHeight > lastHeight ) {
				if ( lastHeight == 0 ) {
					height = clone[0].offsetHeight;
				}
				startWord = endWord + 1;
				endWord = i - 1;
				lastHeight = clone[0].offsetHeight;

				if ( ++lines > maxLine ) {
					break;
				}
			}
		}

		if ( lines > maxLine ) {

			this.css({height: ( lineHeight * maxLine ) + "px", overflowY: 'hidden'});

			part = txt.slice( startWord, endWord + 1 );

			for( i = part.length - 1; i >= 0; i-- ) {

				clone.html( part.join(' ') + moreText );

				if ( clone[0].offsetHeight > height ) {
					part.splice( i, 1 );
					endWord--;
				} else {
					break;
				}
			}

			txt[ endWord ] += moreText;

			self.innerHTML = txt.join(" ");
		} else {
			this.css({height: "auto"});
		}

		clone.remove();
	}
})( jQuery );
</script>
<style>.fvem{width:200px;font-size:14px;border:1px solid #000000;}</style>
<div class="fvem">
	<div class="correct_comment">Loremipsud <div style="font-size:45px">olorsitmet</div>, consecteturad ipiscingelit. Nulla tincidunt nunc commodo magna posuere sollicitudin. Quisque ultrices sodales nisi eu sagittis.</div>
</div>

<script type="text/javascript">
	jQuery(".correct_comment").correctLines( 3, '<span onclick="jQuery(this).parent().css(\'height\', \'auto\').end().hide();">... <span style="color: #f00; text-decoration: underline; cursor: pointer;">more</span></span>' );
</script>