Website url whitelists

I'm building a user content parser and am adding an automatic link parser. I'm addi开发者_如何学运维ng a dialogue, that confirms that the user wants to go to the particular site being linked to. This is for two reasons. Anti phishing and spam combating. However I want to be able to disable both the dialogue and nofollow additions with commonly used websites so I'm building a whitelist. Are there any common whitelists about or should I start building one from scratch?

This may be very useful to you

http://code.google.com/apis/safebrowsing/