The rapier is a really interesting weapon. It evolved from the standard single-handed swords common in Italy in the 1500s. The rapier symbolizes a shift in both culture and combat systems: it was an essentially civilian weapon -- something unusual in the context of its creation.

The fencing system that went with the weapon was transformed from one with dozens of colorful guards like "guard of the unicorn" and "iron door" to one with only 4 guard positions. This was part of the shifts in intellectual thought taking place in Europe at the time. Members of the gentry like Camillo Agrippa remade the conceptual framework for fencing in geometric and philosophical terms.

The rapier also played a big role in the duel, which was a custom that evolved (primarily) out of the vendetta in Italy -- yeah, the Montague and Capulet thing. This one-on-one combat among social elites caught on in the rest of Europe, and eventually became most associated with the French. That might have something to do with the fact that the French were much better at killing each other in duels, while the Italians had a tendency to spend a lot of time arguing about the question of honor in pamphlets. A good place to learn more about this part of the story is The Duel: Its Rise and Fall in Early Modern France, by François Billacois.

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Another interesting weapon is the navaja. This knife was associated with Andalusian criminals in the early 1800s. Many navajas have a ratcheting locking mechanism that makes a pretty loud CLICK-CK-CK-CK noise when opened. There has been some reasonable speculation that the reaction to this sound on the streets of 19th century Spain would be fairly similar to the sort of reaction you might observe when a shotgun is cocked today.