Good idea.
I was thinking of doing that for EU webmasters but the problem is I didn't want to collect money in Euro's (most of my members would be pretty confused over that ;-)). If I collect in dollars and pay in Euros I'm essentially paying a floating currency rate. Paying a stable Euro amount while I collect in a stable dollar amount.
More than 95% of our traffic comes from US based companies so I just decided to stick to US dollars.