How do you pronounce the word "often" ???

I've been interested in this one since my daughter, brought up as an OFF-en speaker, went to college at the University of Michigan and came back saying OFF-ten. I don't think it's a regional thing -- I grew up two hours south of Ann Arbor, and I don't remember OFF-ten even as a variant. It must have been something she picked up from friends.

The variation seems to go quite far back in history. The American Heritage Book of English Usage (1996) suggests that the /t/ was lost in the 15th century, but that "Because of the influence of spelling," often "is now commonly pronounced with the t." That would, as Robert suggests, make the t-full version a spelling pronunciation.

Naturally, the t version has been scorned as both an ignorant goof and a pretentious mannerism. "The bad odor of class-conscious affectation still clings to it," says Charles Harrington Elster in "The Big Book of Beastly Pronunciations." And it's true that OFF-ten deviates from the usual pattern of soften, listen, fasten, christen, etc. 

Much more at the link in the very interesting (and wonderfully-titled) blog Throw Grammar from the Train.