Freemasons

So, I have an acquaintance who occasionally mentions his meetings at the local Mason Lodge.  Up until his Freemason-related Facebook statuses began, my only "knowledge" of the Freemasons was that they are all conspiracy theorists (thanks Dan Brown) and cannibals (thanks Bones).

Now, you're probably going to get all uppity because my "knowledge" isn't even correctly drawn.  Dan Brown's novel supposedly reveals secrets kept from society (making them the target of the conspiracy theorists and not the conspiracy theorists themselves).  But as all prejudiced thinking works, I have drawn easier connections in my mind so that through the novel, the Freemasons = a society for conspiracy theorists to come together to discuss all the things our government is hiding from us.

And about the cannibalism bit- to be fair, the TV show Bones never stated that Freemasons are cannibals.  They just made a fictional secret society that uses architectural clues and symbols to encode information and give off the aura of being the Freemasons, with one exception, and that being that they have also incorporated cannibalism.  So in my preconceived notions of Freemasonry, we've got conspiracy theorists and cannibals.

Enter my friend, who seems to be a level-headed guy not prone to conspiracy theories OR cannibalism.  His Facebook references to the Lodge triggered curiosity.  Well, if they are not eating each other, or discussing whether or not the US put people on the moon, what are they doing?  A quick Wikipedia search revealed nothing useful.

It seems that the Freemasons do not gather at their meetings in order to organize charity fundraisers, sponsor kids, or set up scholarships in any way.  They don't get involved in philanthropy or humanitarian efforts; they don't seem to benefit society in any form at all.  They also don't seem to be a "club" with common interests such as being veterans, involvement in local politics, model airplanes, or quilting.  Nor do they seem to be a white supremacy group.

Does anyone know if this group has a purpose?  And if they do not, how have they managed to be around for so long?  Do they go to their lodge so they can sit around with other men, drink beer, and shake hands?  If so, doesn't that kind of resemble a version of Calvin and Hobbes' club "G.R.O.S.S." but for grown men?  And isn't that kind of ridiculous?

Can anyone clear this up for me, because I really would not like to associate my acquaintance with cannibalism.  Thanks.