I noticed a while ago that google toolbar in both firefox and IE has a very nice feature. As you type a search, it will do an autocomplete based on popular searches. However, if you put in google calculator terms, it will also provide the calculator answer in the dropdown, so you don’t even have to hit enter to see the answer. I used this yesterday, for instance, to determine how many teaspoons it takes to make 1/2 a tablespoon (1/2 tblsp in tsp).