I'm working about , spam prevention on Joomla CMS, so searching on the net i've found this two interesting open source project that helps on detect who are "contacting you". I’m writing two separate plugin for Joomla. I’m currently testing it here on contact form and I hope to make the first release in the next few days.The first plugin taking advantage of the data generated by Project Honey Pot keep information on malicious or suspicious IPs. The second using Iplocationtools.com offers a free geolocation API that lets you query with an ip address and get the location details such as city, country, zip, latitude, longitude etc.