Yahoo’s api provides a CSV dump:
Example: http://finance.yahoo.com/d/quotes.csv?s=msft&f=price
I’m not sure if it is documented or not, but this code sample should showcase all of the features (namely the stat types [parameter f in the query string]. I’m sure you can find documentation (official or not) if you search for it.
http://www.goldb.org/ystockquote.html
Edit
I found some unofficial documentation:
http://ilmusaham.wordpress.com/tag/stock-yahoo-data/