Being both a language enthusiast and a programmer, I find myself often doing programming or text processing involving foreign language alphabets and scripts.
One annoyance however is that CJK fonts (those which support Chinese, Japanese, and/or Korean) usually only contain glyphs for Latin, Greek, and Cyrillic at best. Often the Asian glyphs will be beautiful but the other glyphs can be quite ugly.
Just as often in text editors you can only choose a single font, not one for CJKV and one for other, which will be each used for rendering the appropriate characters.
Korean is one of the languages I'm most interested in currently. I only need hangul / hangeul for monospaced editing, hanja isn't common enough to be a problem.
Another of the languages I'm currently involved in is Georgian, which has its own alphabet which is a little exotic but has pretty good support in common fonts on Windows and *nix.
But I am as yet unable to find a font with good Korean glyphs and also Georgian glyphs.
My editor of choice is gVim, so an answer telling me how to set it to use two fonts together would be just as good. Currently I'm using it mostly under Windows 7 so a vim-specific solution would be needed rather than a *nix-specific solution.