As in: “you read the SDMB? Wow, so do I! What’s your username???”.
Inspired by Dr. Girlfriend’s posting in this thread. http://boards.straightdope.com/sdmb/showthread.php?p=14047589#post14047589.
Alas, I have no random acts of Dopeness to report. We’ve met Dopers, but knew them beforehand and the meetings were planned.
Never met any I know of, although there are and have been others living in the area.
No, but I once had a planned meeting with a couple of Dopers, and it turned out that one of them was living right across the street from me.
I inspired a thread! And it’s not in the Pit! Woo-hoo! 
Not yet, but I always think about the possibility when posting from the train or while getting a to-go order at a restaurant or something.
I was at a friend’s birthday party a couple years ago. Was chatting with one of her friends and the subject of urban legends came up. I mentioned this board and she said she knew someone else who posted here.
Unfortunately, I can’t remember the name of the other poster. (Names here are complicated, like “KyyroyetilamaCat” or something.) I sent PMs to a couple people I thought might be it, but no one recognized the description of the FOAF in question.
In college I discovered there was another Doper living two doors down the hall in my dorm. She’d printed out some jokes from a thread here, attributed to the usernames of those who’d posted them, and put them up as part of her door decorations. I recognized the jokes/usernames and asked her if she was on the SDMB. Turns out she was (and still is) a Doper, although she mostly lurks.
There was a Doper here a few years back who, though I never met her in person, I managed to figure out through her location and various clues in her posts that she was one of my wife’s employees.
I’ve told this story before but it stands well.
WAY the hell back when I’d just started in 2000…
I was attending a gaming convention with a pal and say down to play a big ol’ strategy game like Civilization or Supremacy or something.
And the guy across from me setting up the board had a nametag that read ‘John Corrado’…our very own mod and a good friend of one of my best friends, apparently.
So I says, “John Corrado…do the words Straight Dope Message Board mean anything to you?”
And that was that.
For some time, I was convinced that Rachelellogram was a friend of mine (also named Rachel, you see). Just a handful of similarities in personality, writing style, and a handful of self-descriptors.
Turns out, nope.
Sort of…I ran into a fellow doper on a dating site but didn’t realize it. It was only through an odd coincidence that I put it together. We messaged back and forth for a while and ended up going out to dinner after work one night a few weeks ago (strictly as Dopers).
But other then that, I don’t think I’ve ever run into someone IRL and later realized they were a doper, that I know of.
That same doper showed up in my possible matches on that site, but I recognized her instantly after seeing her pics in the Doper gallery and reading the Online Dating Thread.
There are several Dopers in my city, but it’s never happened yet. I know the neighborhood one Doper lives in, but he’s old enough to be my dad and I probably wouldn’t recognize him if I saw him even though I think I’ve seen him in the portrait gallery. I know another Doper that is closer to my age, but we travel in different circles, but I might recognize him if I saw him and I know his real name too. I don’t know that much about the other Dopers in my city. I can’t imagine why I might bring up the SDMB in real conversation.
I know a couple of Dopers IRL, but they were friends before I became a Doper.
As a very secretive individual, who sometimes has posted quite private information about myself under the anonymity of the internet, I don’t tell others IRL that I post on here.
No random encounters, but one time my mother showed me something she’d printed out from one of Cecil’s columns. She was explaining to me all about the Straight Dope. I just smiled and nodded. Mom’s not a doper, but she knows how to Google to find out answers to her questions.
Didn’t she come to the Ladew Dopefest? How did you explain who we were?
I ran into a couple of Dopers wholly by chance at the Saugus Iron Works a couple of years ago.
Yep. I’ve mentioned this before here, as this thread topic appears from time to time, but when I was temping back in 2004, I was in the cubicle over from Gundy (she doesn’t post much here anymore, but used to be a key part of the Chicago SD contingent). I overheard her talking on the phone about organizing something that sounded suspiciously like a Dope fest. So my first interaction with her (I had already been working there for several weeks) was peeking my head over the cubicle, excusing myself for overhearing her conversation, and tentatively asking whether she was talking about the Straight Dope. I was initially greeted by a somewhat puzzled, blank stare, which made me think she had no clue what the fuck I was talking about, but then she said “what’s your screen name?”
That was the first dope I met IRL, and I still generally keep my message board life separate from my IRL social life.