1. Viagra Men being treated for erectile dysfunction should salute the working stiffs of Merthyr Tydfil, the Welsh hamlet where, in 1992 trials, the gravity-defying side effects of a new angina drug first popped up. Previously, the blue-collar town was known for producing a different kind of iron.
2. LSD Swiss chemist Albert Hofmann took the world's first acid hit in 1943, when he touched a smidge of lysergic acid diethylamide, a chemical he had researched for inducing childbirth. He later tried a bigger dose and made another discovery: the bad trip.
3. X-rays Several 19th-century scientists toyed with the penetrating rays emitted when electrons strike a metal target. But the x-ray wasn't discovered until 1895, when German egghead Wilhelm Röntgen tried sticking various objects in front of the radiation - and saw the bones of his hand projected on a wall.
4. Penicillin Scottish scientist Alexander Fleming was researching the flu in 1928 when he noticed that a blue-green mold had infected one of his petri dishes - and killed the staphylococcus bacteria growing in it. All hail sloppy lab work!
5. Artificial sweeteners Speaking of botched lab jobs, three leading pseudo-sugars reached human lips only because scientists forgot to wash their hands. Cyclamate (1937) and aspartame (1965) are byproducts of medical research, and saccharin (1879) appeared during a project on coal tar derivatives. Yummy.
6. Microwave ovens Microwave emitters (or magnetrons) powered Allied radar in WWII. The leap from detecting Nazis to nuking nachos came in 1946, after a magnetron melted a candy bar in Raytheon engineer Percy Spencer's pocket.
7. Brandy Medieval wine merchants used to boil the H20 out of wine so their delicate cargo would keep better and take up less space at sea. Before long, some intrepid soul - our money's on a sailor - decided to bypass the reconstitution stage, and brandy was born. Pass the Courvoisier!
8. Vulcanized rubber Rubber rots badly and smells worse, unless it's vulcanized. Ancient Mesoamericans had their own version of the process, but Charles Goodyear rediscovered it in 1839 when he unintentionally (well, at least according to most accounts) dropped a rubber-sulfur compound onto a hot stove.
9. Silly Putty In the early 1940s, General Electric scientist James Wright was working on artificial rubber for the war effort when he mixed boric acid and silicon oil. V-J Day didn't come any sooner, but comic strip image-stretching practically became a national pastime.
10. Potato chips Chef George Crum concocted the perfect sandwich complement in 1853 when - to spite a customer who complained that his fries were cut too thick - he sliced a potato paper-thin and fried it to a crisp. Needless to say, the diner couldn't eat just one.