http://www.xmethods.com/ has a lot of these types of services already built..
>I'm looking for suggestions to a problem I'm going to encounter shortly with one of my apps:
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>The application is going to have a cashbook module added that will need to use multiple currencies and will need to regularly check the exchange rates.
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>Ideally, I'd like the desktop app to request this info from a web site so that I have a central place to keep the exchange rates updated (similar to .NET but having a desktop app request the info instead of a website).
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>Does anybody have any ideas? The best I can achieve so far is to have a file on the internet and use FTP to download this but thats a bit scrappy.