Question: What is the most reliable and up-to-date source for getting world currency exchange rates?

Answer: 
[XE](http://www.xe.com/) and [Oanda](http://www.oanda.com/) would be one of your safe bets. And it is in real time too. But a strict no no for using their services. They give very low exchange rates.
[Here's one](http://www.forexdirectory.net/quotesfx.html) that appears to be real time.

If you're wanting to trade, you'll likely get something better than this with your forex trading account.