If you looking for an 'Nirvana' song go to google.com or the google search in this page ( towards the top right side) and type in the below text.
-inurl:(htmhtmlphp) intitle:"index of" +"last modified" +"parent directory" +description +size +(wmamp3) "Nirvana"
Just substitute the term "Nirvana" for any band or singer you might be looking for, and your search will lead you to open indexes that contain downloadable music files.. try it to believe it. or on the other hand you could use sites like http://www.ironlab.org/projects/findmusic.php or http://www.goofile.be./
With some slight modifications the same search string can easily be used to search for ebooks in DOC and PDF format:
example: if you are looking for george orwell 1984
-inurl:(htmhtmlphp) intitle:"index of" +"last modified" +"parent directory" +description +size +(pdfdoc) "george orwell 1984?
Friends, if you know some more feature do add in your comments to this article..