Logged in users have been able to set their timezone preference for a while (event announcements converted for you automatically). I've added currency preference now as well - the store pages and widgets are using it, I will start to add other parts of the site soon as well. Here is an example of what a store page looks like with my USD preference:
To update your own preferences, click the Edit Profile button at the top of the My Account page.
I've added eBay listings to the currency logic as well. For ended items, if the site has currency info, it will show what the exchange rate was on that day - if not, no conversion is currently shown. This will become more useful moving forward than for already ended items, of course.
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