Omer van Kloten's entry on Internationalization of Programming reminded me of a (possibly apocryphal) story that I was told when I started working on OLE Automation. I asked why IDispatch::GetIDsOfNames takes an LCID and was told that once-upon-a-time, the VBA team conducted an experiment in localization with VBA in Excel (which was the first application to host VBA). Apparently, they attempted to localize the entire language--keywords, function names, etc.--into French, and possibly other languages. This mean you could write code along the lines of what Omer outlines in his entry, except in French instead of Dutch.
The problem was that because VBA wasn't exactly compiled in those days, the Excel spreadsheet that you wrote your code in now depended on having localized Excel on the machine. If you sent your spreadsheet to your colleague in New York, they couldn't run the macros because their English Excel didn't understand the language...