Best hack utilizing end-of-day stock price data (provided) for companies trading on the NYSE, AMEX and NASDAQ stock exchanges.
This is an example of how to access "GOOG" stock ticker information directly from Yahoo Finance. http://ichart.yahoo.com/table.csv?s=GOOG&a=0&b=1&c=2000
Their API doc is also included below if you wish to use another API https://code.google.com/p/yahoo-finance-managed/wiki/csvHistQuotesDownload