David Heinemeier Hansson, the creator of Rails, gave a talk on the startup school. Take a look at the video, is really interesting:

http://www.justin.tv/hackertv/97862/DHH_Talk__Startup_School_2008

He says "Stop trying to create the next Facebook or the next MySpace", "There are a lot of other small apps that can make you earn enough money to make you live in peace"

He's so right, some people spend their lives trying to hit a home run or trying to create the application of their dreams. Why don't just create something good enough for a bunch of potential users and earn some money from them. If it becomes bigger... great, it not, we have another income.