I have been using this chart, to check the Yen vs the US dollar, and it's helped me save a few bucks here and there. The most I saved so far was $11 off a order with shipping, compared to if I ordered the day before. That's money to spend somewhere else

http://free.charts.xe.com/misc/xe.asp

click file and change symbol to USD/Japan. you can set for minutes or hours.

Or if you're just curious as to the currency rate:
http://www.xe.com/
From the same place that tinman linked. Very helpful when you want to order something from the EU and other parts of the world and want to know what the price is in USD.

I have a currency conversion widget on my desktop. It's all I ever need.

XE is a great site. nice post.

You can also type '1 usd to yen' or whatever into google for a conversion.
Works for any type conversion.

That is such a great widget! (I just switched from XP to a new iMac and am lovin' it.) In the past I've used the coinmill.com site by bookmarking the yen-to-dollars page.

Truth be told, I don't really use converters much any more. I just move the comma in the Yen price one place to the right, think of is as a period instead of a comma, and think "there's my USD amount." It's not truly accurate and tends to yield a slightly higher cost than the real one, which difference I call "shipping." Given the relative stability of Yen/Dollar rate ratios over the past several months, it works for ballpark estimates on the fly.