How do I use getUrl to get specific data off a web page?

How do I use getUrl to get specific data off a web page?

Hello,

I've figured out how to place the string data from getUrl into a variable but once I save the URL to a variable, how do I actually extract JUST the exact data field I want from the webpage?

For example, if I use either one of the two links below, how would I get the last trade price from the webpage?
http://www.google.com/finance?q=aapl
OR
http://finance.yahoo.com/q?s=goog

I know the price is somewhere in the resulting string from getUrl, but I don't know how to zero in on just the price data.  Sorry if this is obvious but I just can't seem to figure it out.

Thanks so much for your help.