Microsoft's Windows live search http://www.msn.com/ or http://www.live.com/ seems to be the most powerful search tool for webometrics now - follow the link below for its help pages. See the section on keywords in particular.

http://help.live.com/(bWFya2V0PWVuLVVTJnByb2plY3Q9V0xfU2VhcmNodjE=)/Help.aspx?querytype=topic&query=WL_SEARCH_REF_AdvancedSearch.htm&fs=1