Como me quedaron lindos se los comparto para que los usen si les hace falta.

Bocadillos con CSS

CSS:

.comentario {
    background-color: #336699;
    width: 600px;
    padding: 20px;
    float: left;
    color: #fff;
}

.contenedor {
    float: left;
}

.comentario.der {
    float: left;
}

.comentario.izq {
    float: right;
}

.comentario.top {
    float: none;
}

.comentario.bot {
    float: none;
}

.bocado-izq {
    border-bottom: 20px solid transparent;
    border-right: 25px solid #336699;
    border-top: 20px solid transparent;
    height: 0;
    width: 0;
    float: left;
}

.bocado-der {
    border-bottom: 20px solid transparent;
    border-left: 25px solid #336699;
    border-top: 20px solid transparent;
    height: 0;
    width: 0;
    float: right;
}

.bocado-top {
    border-bottom: 25px solid #336699;
    border-left: 20px solid transparent;
    border-right: 20px solid transparent;
    height: 0;
    width: 0;
}

.bocado-top_mid {
    border-bottom: 25px solid #336699;
    border-left: 20px solid transparent;
    border-right: 20px solid transparent;
    height: 0;
    width: 0;
    margin: 0 auto;
}

.bocado-bot {
    border-left: 20px solid transparent;
    border-top: 25px solid #336699;
    border-right: 20px solid transparent;
    height: 0;
    width: 0;
    float: right;
}

.bocado-bot_mid {
    border-left: 20px solid transparent;
    border-top: 25px solid #336699;
    border-right: 20px solid transparent;
    height: 0;
    width: 0;
    margin: 0 auto;
}

.clear {
    clear: both;
}

HTML:

<div>
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        at sapien accumsan consectetuer.Lorem ipsum dolor sit amet,
        nulla viverra diam faucibus dictum. Nulla facilisi. Donec sit amet dolor
        at sapien accumsan consectetuer.
    </div>
    <div></div>
</div>

<div></div>
<br/>

<div>
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        at sapien accumsan consectetuer.Lorem ipsum dolor sit amet,
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        at sapien accumsan consectetuer.
    </div>
    <div></div>
</div>

<div></div>
<br/>

<div>
    <div></div>
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        nulla viverra diam faucibus dictum. Nulla facilisi. Donec sit amet dolor
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        nulla viverra diam faucibus dictum. Nulla facilisi. Donec sit amet dolor
        at sapien accumsan consectetuer.
    </div>
</div>

<div></div>
<br/>

<div>
    <div></div>
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        at sapien accumsan consectetuer.
    </div>
</div>

<div></div>
<br/>

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        nulla viverra diam faucibus dictum. Nulla facilisi. Donec sit amet dolor
        at sapien accumsan consectetuer.Lorem ipsum dolor sit amet,
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        at sapien accumsan consectetuer.
    </div>
    <div></div>
</div>

<div></div>
<br/>

<div>
    <div>Lorem ipsum dolor sit amet,
        nulla viverra diam faucibus dictum. Nulla facilisi. Donec sit amet dolor
        at sapien accumsan consectetuer.Lorem ipsum dolor sit amet,
        nulla viverra diam faucibus dictum. Nulla facilisi. Donec sit amet dolor
        at sapien accumsan consectetuer.
    </div>
    <div></div>
</div>