Positioning element at bottom of div

Good evening.
I’m doing a “construction page” of the company I work for, and I came up with this question of how to position the div element at the end.

I have the following layout:


In part that is red, where it will be social networks. With the site, shown below the image, you will understand.
Another doubt, to some resolutions, the footer was above of the div of social networks:

How it is:

As was to stay:

From now, thanks
-Sorry, for my english-

on the element you want at the bottom of the div, try

margin-bottom: 0px;

Nothing ):
I tried in #elemento {}, #elemento ul li {} and #elemento ul li a {}, and none effect.

Obs: Sorry, I forgot the code!

        <div id="container">

        <div id="logo"><!--<img src="imagem/pps2web.png" alt="" />--></div>
        <div id="conteudo">
                <p><img src="imagem/construcao.gif" alt="Intimesoft Sistemas" /></p>
        <div id="redes_sociais">
                <div id="elementos">
                    <li><a href="http://intimesoft.com.br/os/" target="_blank"><img src="imagem/contact.png" alt="" /></a></li>
                    <li><a href="http://twitter.com/#!/intimesoft" target="_blank"><img src="imagem/twitter.png" alt="" /></a></li>

                    <li><a href="http://www.facebook.com/pages/INTIMESOFT-SISTEMAS/273946635978712" target="_blank"><img src="imagem/facebook.png" alt="" /></a></li>
    <div id="footer">
            <div id="rodape">
                <div class="endereco">

                        <li><p>Rua Joaquim Nabuco, 634 - Farol. Maceió. AL | 82 - 3313.0345 // 9965.2179</p></li>
                        <li><p>© 2000 - 2011 | Intimesoft® Software Ltda. Todos os direitos reservados.</p></li>

html, body {height: 100%;}
* {
    margin: 0 auto;
    padding: 0;
    border: 0;
    font-size: 100%;
    font: inherit;
    vertical-align: baseline;
    list-style: none;

#container {width: 900px; margin: 0 auto; padding: 0; font-family: 'Abel'; min-height: 100%; height: auto !important; height: 100%; clear: both;}

#logo {width: 900px; height: 262px; margin: 0 0 10px 0; padding: 0; background: url(imagem/logotipo.png) no-repeat;}

#conteudo {width: 894px; height: 250px; padding: 3px; margin: 40px 0 0 0;}
#conteudo p {text-align: center; margin: 0 0 10px 0;line-height: 45px; font-size:20px;}
#conteudo img {margin:0 10px 0 0; vertical-align: middle;}

#redes_sociais {width: 900px;}
#elementos ul li {display: inline; margin: 0; float: right;}
#elementos ul li a {margin: 0 3px; float: right; cursor: pointer; }

#footer {background: #3242DE; margin: 0 auto; border-top: 5px solid #999; list-style: none; position:absolute; bottom:0; width:100%;}
#rodape {width: 950px; margin: 15px auto; padding: 0; list-style: none;}
.endereco {padding: 0 0; margin-top: 70px; width: 690px; padding: 10px;}
.endereco p {font-family: 'Abel'; font-size: 15px; text-align: center; color: #FFF;}

.clear {clear: both;}

Anyone can help me? :confused: