Another addition to the list of useful things Google will report in its search results without sending you to another page: currency conversion. Type in a query like "10 USD into AUD" and a relatively current conversion will appear.
Google Operating System reports that the conversion option has been enhanced to include the trading history for selected currencies, but I couldn't get that to work via the Australian Google site. In practice, for most of us a current figure is more useful anyway. The results work most predictably if you use currency codes, but Google does a reasonable job even with more general queries. As usual, you probably won't get quite that rate when you actually make a purchase, but it's handy for getting a ballpark figure.