ships tracking sites/devices

I have been looking for a millennium yacht for Staluppi for some time and to my surprise found it with an online shiptracking system.
(see link) below.
Must be a yachtspotters wet dream.
Anyway, i suppose more of these services must be available;
question; anyone nows other services like these?

http://ais.qps.nl/InfluxPortal/DesktopDefault.aspx