there is no problem ;every time you are browsing the page you see are save in your browser temporary directory
for example.For that you have to set your windows to see hidden file
for internet explorer is Documents and settings ->Your user name(example Fred)->Temporary Internet File->Content IE
than search in inside directories and files
And by the way to be a good web designer you don't have to copy other people work; maybe you want to learn how to do it ,but you need the source
use a sothink decomp software for that