Addendum: In an earlier version of an article I had written, based on what I was told by some people in Guatemala, about the use of vos in that country. Since then, I have received these comments:
Comment 1: I have to agree with your article, however, on this paragraph, the rule that a man would never use vos to address another man is not quite accurate.
As a matter of fact, I would never use tú with my buddies. It sounds too ... awkward.
I grew up in Guatemala, la capital to be specific. Here are some conversation examples of how I use tú/usted/vos (this is in no way a representation of how everyone else in Guate uses them):
- To a male friend: "Vos Humberto mano, a la gran pu--, porque no la llamaste!"
- Between my parents(*): "Hola mijo, como está? Ya almorzo?" (They use usted to address me). "Sí mama, estoy bien, y tú como estas?" (I use tú to address them.)
- To a girl I just met or an acquaintance: Usted is the universal rule.
- To a girl who is very close: "Claudia, te gustaría ir a comer algo?" Tutear is the term used when a guy and a girl reach the comfort level to refer to each other using tú.
- To my sister(**): "Vos Sonia, a qué horas vas a venir?"
(**) Some of my friends address their siblings with usted.
Comment 2: The usage of vos and tú is interesting because it is an important element in the regional characteristics of the language and social relationships. What the other Guatemalan user pointed out in his clarification is true. Vos is used when there is a lot of familiarity, but if used out of the familiarity context it can be disrespectful or impolite. In fact, some people use vos in a disdainful way to address a Mayan stranger, but use the formal usted when addressing a ladino (non-Maya) stranger of equal or "higher" social level. In other cases, using vos with a stranger is regarded as rather friendly than impolite, but this is a deeply rooted cultural and social element that can't be described in just a few lines.
Between male friends, vos is indeed the predominant form. Using tú between men is very rare, and it is often characterized as queer. Vos is also used between close female friends, and relatives and friends of whichever sex, to a lesser extent. However, whenever tú is used, it's conjugated as with vos (e.g., tú sos mi mejor amiga. Ana, tú comés muy poco). The use of the traditional conjugation of tú is very rare.
In some cases, the use of vos, tú or usted is not mutual. Sometimes, a person will address you in either way, and you in turn will address that person with a different pronoun. This can be seen with people from different generations, social groups or levels, sexes or even a peer, depending whether you want to show respect, friendliness, distance or simply because that is the way you are used to address a certain group. This explains the example of the other Guatemalan, where his mother uses usted and he uses tú, and how he addresses acquaintances or women with usted, which is due to the way he is used to address them within his social sphere.
This is true for all social levels of ladinos in urban areas and many rural areas. Some things vary with people of Mayan descent.

