For many search sites firefox lets you add them to the search box with one click, too (the little triangle glows blue or something like that). Also you can set a code for each search engine (like 'g' for google, 'wj' for Japanese wikipedia) which you can use in the address bar. For example you'd only have to type 'wj 芥川龍之介' to search the term on wikipedia. This may speed up your search a little.