Fiddle: http://jsfiddle.net/iambriansreed/bjdSF/
jQuery:
jQuery(function(){
var minimized_elements = $('p.minimize');
var minimize_character_count = 100;
minimized_elements.each(function(){
var t = $(this).text();
if(t.length < minimize_character_count ) return;
$(this).html(
t.slice(0,minimize_character_count )+'<span>... </span><a href="#" class="more">More</a>'+
'<span style="display:none;">'+ t.slice(minimize_character_count ,t.length)+' <a href="#" class="less">Less</a></span>'
);
});
$('a.more', minimized_elements).click(function(event){
event.preventDefault();
$(this).hide().prev().hide();
$(this).next().show();
});
$('a.less', minimized_elements).click(function(event){
event.preventDefault();
$(this).parent().hide().prev().show().prev().show();
});
});