"There is no such thing as an accident," Napoleon Bonaparte once said. "Only a failure to recognize the hand of fate." Leaving aside the emperor's own igno­minious fate (squalid exile on a remote island in the South Atlantic), any growth-focused, get-'er-done entrepreneur on the Inc. 5000 would surely have a bone to pick with Bonaparte: There are accidents, and what determines your future comes down to how quickly and creatively you respond to them. Here, four cases of inspired innovators who turned a mishap into millions.

Post-its: The Heaven-Sent Office Supply

The story behind the Post-it is actually a tale of three compounded accidents. In 1968, Spencer Silver, a chemist at 3M, wanted to create an incredibly strong adhesive but--and there's no gentle way to put this--he bombed miserably. The adhesive he eventually concocted could hardly have been more feeble.

Ever the optimist--or opportunist--Silver saw an upside: It was pressure sensitive and restickable. Stick it you-know-where, said the 3M brass. Where it stayed for six years. Until Arthur Fry, a fellow 3M scientist who couldn't seem to keep his bookmark in his church-choir hymnal, had a moment of divine inspiration: Silver's restickable adhesive, he thought, might hold his spot without damaging the book's pages. As Silver and Fry developed what they envisioned as a breakthrough bookmark, they started using the sticky notes around the office in what Fry later described as "a whole new way to communicate," which they shrewdly realized had even more potential than their original idea. Oh, and the signature Post-it yellow? It was selected by neither great gut instinct nor almighty focus group; it was the only color paper the lab next door could spare.

Microwave Oven: Total Meltdown

 inline image

Percy Spencer was conducting an experiment when the candy bar in his pants pocket suddenly--and weirdly--melted. The Raytheon engineer had been trying to improve radar, and posited that microwaves had caused the candy to warm, soften, and create the embarrassing situation in his trousers.

Now what? Spencer could have turned his inventor's mind to creating a heat-resistant candy bar wrapper or a fast-acting stain remover, but instead he focused his attention on snacks. He tested popcorn. He tested eggs. (While observing the fast-cooking effects of Spencer's microwaves, a skeptical co-worker literally got egg on his face.) In 1947, Raytheon unveiled the first microwave oven--the Radarange. It flopped spectacularly. Big as a fridge and more expensive than the average car, the microwave oven languished until 1967, when a countertop version debuted. After that, the market heated up: Today, some 90 percent of American households own a microwave.

Super Glue: Another Sticky Situation

 inline image

It was 1942, and every American chemist worth his or her NaCl was helping the war effort. Harry Coover's team at Eastman Kodak was no exception. Their goal: a compound to be used in clear-plastic rifle sights. Unfortunately, the concoction Coover created had one problem: It stuck fast to everything it touched. The adhesive was unceremoniously sidelined. But nine years later, Coover and a colleague, Fred Joyner, revisited the sticky formula while working on another military project and found it useful as a quick-drying, insanely strong glue. It was not-so- cleverly called Eastman #910, then not-so-cleverly rebranded as Eastman 910, and then licensed by a company that not-so-cleverly re-rebranded it Loctite 404 Quick Set. Eventually, Super Glue emerged, as did a competing cousin, Krazy Glue.

Coover's super sticky glue would eventually find a military use, too: In Vietnam, combat medics used his adhesive as a stitchless suture. In 2010, with more than 450 patents under his belt, Coover received the National Medal of Technology and Innovation from President Obama.

Saccharin: The Upside of Dirty Hands

 inline image

If you were in the hunt to create an artificial sweetener, chances are you wouldn't start with a dark, viscous coal-tar derivative used for treating psoriasis and preserving railway ties. And indeed, when post-doc chemistry student Constantin Fahlberg was mucking about with coal tar in a Johns Hopkins University lab one night in 1878, sweetening was far from his mind.

But when he dashed out of the lab and got home for dinner, Fahlberg noticed that his bread and, in fact, everything he touched tasted sweeter than usual. Having neglected to wash his hands, he'd "contaminated" his food with the chemical compound he'd been working on. Ever since, saccharin--300 times sweeter than sugar! No calories!--has fallen in and out of favor as a sugar substitute, earned hundreds of millions of dollars a year, and been the focus of government testing and regulation. And, of course, packets of saccharin-containing Sweet'N Low have been stolen from restaurants in all 50 states.