I've seen this asked before but never seen the "right"/complete
answer.  

For a school project I need to do analysis on stock data.  I
am a programmer, so I'm looking for data feeds, but it can be XML, it
can be HTML, it can be anything I can parse.  But it should be
something that the site permits me to use (even if I have to pay a
reasonable fee for it).

So, for example, I want to be able to be able to ask this "dataset"
what was NASDAQ:AAPL at 8:20 am February 2, 2006.  I know sites like
Google's Finance display this sort of data, but I want to query it
programmatically.  Also, their data is the 15 minute delayed stuff,
and I would also like to know how to get access to the live data
programmatically.  If something provided both historical, new 15
minute delayed, and "real-time" (for a reasonable fee or something)
that would be ideal.  It would be ideal if I could request ranges, so
I could say, give me all the stock price data for NASDAQ:AAPL from
2005 and it would return me all the prices at whatever time increment
I specify.

I would also like it to provide me access to the list of listed
companies per exchange, so I can do queries against unpoopular, little
known companies.

It probably doesn't matter in that the data feed would likely be XML
or CSV or text or HTML or something, but in case it matters, the
language I'd be using would be PHP or Java.

Thanks.

I think the problem is that access to this kind of data is not usually
cheap, at least from no source I know.  The fees for real-time data
are not too bad, and you can get real-time island data for free  The
kicker is getting access to a system that has data fees for
everyhting.  Usually thing what be provided by your school, if they
require you access it.  For instance, the Bloomberg api or Reuters api
could give you this, but that is extremely expensive.  Wombat offers
this also, but I don't know the fees. I am guessing: exhorbitant. 
Hopefully the researches can track down a provider that is cheap, but
don't bet on it.  The reason this stuff costs money is because 1)there
is a large market for it and 2)it takes a complicated network and
software infratructure to provide these kinds of data feeds.

With respec to lists of companies, you are probably best off getting
lists of index components.  You can get this in spreadsheet format off
of yahoo finance.  If you want small companies, just look for the
Russel 2000 or Wilshire 5000.

just re-read this. "data fees for everything" should read "data feeds
for everything".