What are some great startup business stories?

Airbnb - originally achieved "ramen profitability" through selling Obama and McCain themed cereal while working on the product. They made money on the Obama O's (which were a huge success) but had to eat all the Cap'n McCains to stay alive and within their budget. Video of the story: http://www.justin.tv/startupscho...Foursquare - a product idea way ahead of its time. Dennis Crowley founded Dodgeball in 2000 and sold it to Google in 2005. It languished, so he left and launched foursquare at SXSW 2009. It now has 10M+ users.StumbleUpon - founded in 2001, bought by eBay in 2007 for $75M but languished, the founders bought it back in 2009 for a reported $29M and it recently hit 1B stumbles per month.