Y Combinator: You Want to Be a Billionaire?

wice a year, close to 200 teams of aspiring tech entrepreneurs, most in their 20s, converge on Mountain View, in Silicon Valley, vying for a spot at Y Combinator, the seven-year-old seed-funding firmâ??cumâ??accelerator co-founded by venture investor Paul Graham. Their dream: becoming the next Y.C.-backed sensation, like Dropbox, Airbnb, or OMGPOP. In an adaptation from his new book, Randall Stross follows one of the summer 2011 start-ups from tryout to â??Demo Day,â? to see what it takes.