[nervechannel]

That's the point, what I want is exactly a user-specific blacklist.

I can even do that already with Google's Custom Search, all that's missing is a little 'block this site' button. Instead I have to go and configure Custom Search manually for each URL mask.

[jimmyswimmy]

You could write a little GreaseMonkey script or extension to do that, shouldn't be too hard.