frontpage - 1:46 pm on Feb 10, 2011 (gmt 0)
One of the simpliest methods of avoiding contact page spam?
1) Rename your contact page to something obscure. Don't use 'contact.php' or 'contactus.php'.
2) Add the 'noindex' meta to your contact page header. You don't want spammers finding your contact page in the SERPS.
This will drastically cut down on automated spam attempts.