What is "mesorah?"

For about the past year, I've been tossing about the idea of the "mesorah": things that we do as Orthodox Jews that have no basis in halacha.  Some of them remind me of an old story: A man once watched his wife prepare a roast.  Before she put it into the roasting pan, she cut off the ends.  Her husband was fascinated.  "Why are you cutting off the ends?"  he asked.
The wife shrugged.  "We always prepared a roast that way."  The husband called his mother-in-law and asked him about it.  She told him the same answer--we always did it that way.  That night, the mother-in-law called HER mother and related the story.  The bride's grandmother was silent for a moment.  "Do you still do that?" she asked.  "Of course," the mother-in-law answered.  "Didn't we always prepare roasts that way?"
The bride's grandmother shook her head.  "Honey," she told her daughter, "I only did that because all my pans were too small to hold a whole one!"
So it seems with mesorah.  A lot of traditions that seem to be passed down "from Sinai" are actually responses to conditions that no longer exist.  Some of them are less than a century old--pretty meaningless in a religion that spans over three millennia.  Here are some examples:

• falshe fish on Pesach--originally there were concerns about the materials that fish were wrapped in.  Since we use plastic, I doubt it's an issue anymore.
• The Yiddish language--it's a medieval German dialect
• fedoras--not only are they less than a century old, they were originally women's hats!
• Extensive silver collections--who could afford them in the shtetl?
• Bais Yaakov schools--the first one opened in 1917
• Black clothing--probably a leftover from an Eastern European sumptuary law
• About 90% of the laws of tzinut--most were codified by 20th century rabbis.
• Cholent on Shabbos--it shows the world that we're not Karaites.
• Two kitchens in one--again who could afford it in the shtetl?
• A culture of full-time yeshiva bochurim--even Rashi had a day job.

Can anyone think of any others?