The RSA Laboratories' Frequently Asked Questions About Today's Cryptography was first published in 1992 and has been one of the most popular sections of RSA’s Web site. 

The latest revision, version 4.1 is from 2000.  While quite outdated, still remains a valuable introduction to the field.  It is available free at 

No idea why RSA stopped updating it, as the crypto faq was one of their best marketing efforts. 

Note to RSA Marketing - you will get more publicity and name recognition with an updated FAQ than those silly little trinkets you give out at conferences.