I have come to realize how hard it is for a everyday programmer to get access to even the most basic factual data. If you want to experiment with a new driving directions algorithm, it is infinitely more difficult than coming up with an algorithm; you have to hire a lawyer and a sign a contract with a company that collects that data in the country you are developing for. If you want to write an open source TiVo competitor, you need television listings data for every cable provider in the country, but your options are tenuous at best