For me, it was a link posted by the misanthropic bitch.
How about you, how’d you get here?
hmmm… your link didn’t work for me…
But what brought me here? A LOT of free time on my hands, and a low threshold for boredom! 
Kilgore Trout told me about it after he did a search trying to figure out what those white spots on his fingernails were all about…
Heheh.
I used to watch the TV show on A&E. When I got online, I typed http://www.straightdope.com on a whim. I read the columns for a few weeks before getting on the boards. IIRC, it was the “whispering on submarines” thread that made me decide to register.
It’s all Rasa’s fault.
Of course, she’ll disagree and say it’s all my fault that she’s here in the first place. But she’s wrong. It’s her fault.
Your link spat the dummy.
As to what brought me here - It was my computer. 
I disagree. It’s all zyzz’s fault.
I honestly can’t remember. I think I just stumbled across it.
I blame Rasa too. It’s all her fault.
I take full responsibility for ya, scratchie.
A friend from another message board
was looking for a new place to be on,
her name is Sherry and she called herself sortawicked here,
she was only her for a little while.
But, anyway, she told me about this place
and I’m still here.
I have her to thanks for so much
since I found Montfort here
and of course I have already done that.
The article on the caloric content of sperm brought me to the books/articles, and the thread on the seti@home project got me to join.
my friend sent me a link, so i read the forums for a few days… then i decided to register
I found my way to the boards from the Chicago Reader website, which I had been using and still do use for things like apartment hunting, movies reviews and schedules, and restaurant reviews.
When I noticed the link to The Straight Dope, I was psyched because I got turned onto Uncle Cecil when I was an undergrad, and when the first Straight Dope book came out I sent it to all my relatives for Xmas. After reading the columns in the archives, I clicked on the mesage board link to see what it was, and I was hooked. After lurking for a couple of months, I registered to throw in my occasional comment.
I found the site while browsing through AOL’s content. I recognized “Straight dope” immediately as I’d bought one of Cecil’s books bearing that title years ago. So I clicked on a link which took me to http://www.straightdope.com and spent a few weeks sifting through the online columns (I think I read all of them). After a few weeks of visiting the site here and there, I wondered: “what’s this “message boards” hyperlink I keep seeing?”
So I clicked it and…
here I am! Wooo!
My SO and the other couple we hang with were posting from a coffee shop.
I think I got here through www.snopes.com a couple years ago, but until a few months ago, I looked at the boards maybe once or twice. I did, however, faithfully follow the Great One’s sagacious word every Monday, and was peeved when the new column was late.
However,I visited in time for the original evil nazi groundhogs thread with Scylla, which really got me intrigued. The thread doesn’t seem to be out there anymore - the second thread is, but I don’t see the first, or I’d have linked to it.
I’ve been lurking on 'n off since.
Tisiphone
I was bored at work & did a websearch on yahoo on the word bored…this took me to http://www.bored.com which had lots of interesting links, including one for the columns.
I came from SAAN aka Smile and Act Nice…
(loony is the name)
dogy
I used to read Cecil’s article in a local paper. When I saw that he had books out, I went and read every one available. The next obvious step was to check out the website.