PDF Password Cracker Professional edition allows to search for "owner" and "user" passwords with brute-force and dictionary attacks, effectively optimized for speed (however, don't expect to recover long passwords in a reasonable time with these attacks). In addition, it has Key search attack, which guarantees the decryption (regardless the password length and complexity) of PDF files that use 40-bit encryption (the attack takes about 3-4 days on fast CPU systems).

http://www.crackpdf.com/
PDF Password Cracker Pro 3.0

eller go for:
AAA PDF Password Remover can be used
to decrypt (recovery, remover, unlock) the
owner Password protected Adobe Acrobat PDF files

http://www.aaapdf.com/pdf-password-remover.htm

eller
VeryPDF PDF Password Remover v3.0
og manger andre

ranvik: begge må betales for o.s.v. glemte og skrive at det helst bør være gratis

kan ikke noe slikt som rainbow tables (eller noe sant. har ikke satt meg inn i det) som også kan "låse" opp ande filer brukes?

glemte et punktum i første posten ( skal være to ord etter linken)