Very useful to filter the search! I like the option that hide "block this domain" in the results. Maybe it would be good to have it in the context menu?
Suggestion: add a support for wildcards ? and *, as it doesn't seems to work now. (For instance *.fr doesn't block everything with a .fr domain). Other suggestion: add a feature to block also the access for the site. For instance, if I want to use the addon as a parental control, the child could search in Google, or typing directly the URL, or some site could redirect me to the URL I don't want. But it would be probably good to make another extension for this feature, to let this one light in weight.