The mob movie Donnie Brasco introduced the following (probably made-up) bit of gangster lingo:
introducing someone as “a friend of ours” means that he is a made man (i.e. a true member of the Mafia)
introducing someone as “a friend of mine” means, not a made man, but he’s OK (I vouch for him)
I think that geeks should adopt this convention. When a geek introduces someone to another geek, there should be three alternatives:
1) “have you met X? He/she’s a friend of ours [fellow geek]”
2) “have you met X? “He/she’s a friend of mine [i.e. a product manager/journalist/writer/marketer/corporate-officer, but OK – I vouch for him/her, at least for now]
3) simply “have you met X?”
(And yes, even though I am now (in a friend’s tripartite taxonomy) a “management puke” (the other two alternatives being “engineer” and “marketing fuck”), I am still a “friend of ours”, dammit 🙂 …)
Tim Converse 
There are some people whose role changes depending on the context.
The engineers see me as a marketing fuck. But the marketing fucks don’t want me, so they see me as a management puke. And of course, the management pukes don’t want me, so they see me as one of those expendible engineers they’re regularly trying to outsource and offshore.
So depending on who’s introducing me to whom, one could use any of the three lines when introducing me.
*If* there were someone in the world left for me to be introduced to, that is.
Maybe the line for me should be, “Have you met Adam? He orders the ‘Moron Bowl’ at Nola…”