I have launched a new service that gives the tickers for all MtGox currencies and computes a synthetic Forex grid
based on those tickers.http://bitcoin.clarkmoody.com/ticker/
The Forex grid lists the exchange rate between currencies based on buying Bitcoin with the "column" currency at the Ask and immediately selling those Bitcoin at the Bid for the "row" currency. The grid lists only those currency pairs with non-zero volume as listed on the ticker.
Since the MtGox WebSocket broadcasts ticker & depth messages for USD only (at this point), this tool is polling-based. The update rate is every 60 seconds, and the cells will change colors based on changes in the value.