Google guys are really a bunch of supermen when it comes to innnovation and intellect.
Google has introduced currency conversion in their calc module. For those who dont know about it give a mathematical expression where u give a search string and search for it. It will actually give u the result.
Now type the following string "100 USD in INR" .... and BINGO!!! u'll get the perfect conversion according to current exchange rates. Try it out with other currency codes like GBP ( great britain pound i guess) etc. I am really starting to love google( no man i was already in love with it for its searching capabilities.... in that case i'm loving it more :-) )