Zip Password "Recover" tool needed

hi there. the situation is like this: my *stupid* teachers love to password protect their zip and pdf files on their web pages - i don´t really know why, most of the time they aren´t the autors of the texts, they just google for the subjects or copy books and put the info together on files for us to download. the thing is that they don´t usually tell the password unless you ask for it. now, as the exams are very very near, i won´t be able to talk to this sick bastard who were suppose to teach Computer Networks 2. even if i did, he would laught at me because i tryied to download the files so late - i study little, yeah, and i don´t go to his classes.

So, any one knows a good cracker tool for zip (mostly) and pdf files? thx

http://www.openwall.com/john/

i have john the ripper installed but does it work with this kind of files? i thought it was only for login passwords..
actually, i don´t know how to use it:/ yet.