I see on the Google Security Blog that Google have launched a Safe Browsing api.  In other words, Google are making available its dynamic blacklist of phishing and malware sites so ISPs and web app coders can check against it.

This should help ensure unwitting users are notified before they browse to to unsafe sites and submit their confidential information.

Google are actively encouraging 3rd party participation –

Sign up for a key and let us know how we can make the API better. We fully expect to iterate on the design and improve the data behind the API, and we’ll be paying close attention to your feedback as we do that. We look forward to hearing your thoughts.

Great idea guys.