Want some Honey? with or without a Pot?
These guys have a good article on how to watch for hackers looking to break into yoru website, what techniques they use and how you can secure your system.
They offer open systems on the web with 'special' wrappers that allow them to watch their system getting hacked (and not let them get toooo far, I presume).
Some other good articles here from their other contributors on similiar stuff around "honeypotting"