The CAPTCHA technology might be helpful: http://weblog.infoworld.com/udell/2004/12/01.html#a1124 There are apparently open-source implementations of CAPTCHA, might be something to consider. Another suggestion would be boost-specific CAPTCHA that asks you to enter a result of some enable_if statement as the answer to the question - guaranteed to stop spammers AND newbies! (an unexpected benefit?) regards, max This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail.