One of the community-provided YQL tables looks like it will work for you: yahoo.finance.stocks.
Example YQL query:
select CompanyName from yahoo.finance.stocks where symbol="TKR"
Update 2012-02-10: As firebush points out in the comments, this YQL community table (yahoo.finance.stocks) doesn't seem to be working correctly any more, probably because the HTML page structures on finance.yahoo.com have changed. This is a good example of the downside of any YQL tables that rely on HTML scraping rather than a true API. (Which for Yahoo Finance doesn't exist, unfortunately.)
It looks like the community table for Google Finance is still working, so this may be an alternative to try: select * from google.igoogle.stock where stock='TRK';
