Why does being able to speak in Japanese imply geekdom?
I'll assume here that the speaker is neither culturally Japanese nor in Japan. Even under that assumption, being able to speak Japanese probably doesn't imply geekdom too strongly -- strictly speaking it's evidence for it, but most anime fans never learn the language past a few catchphrases, and it's not that uncommon a language in the West as non-Western European languages go.
However, using a Japanese phrase in a casual context implies quite a different set of things. You might be using it as tribal attire, which probably means you're an anime fan. Y...
Is there any rationalist equivalent of "good luck"? I've tried a few variants, such as "work well", "knock them dead", "we're with you" and certain situation-specific phrasings, but haven't found anything that worked generally - though a hearty "may all the gods of Olympus be with you!" can serve. Not a vitally important point, but it would be nice to have something similarly supportive and yet accurate to say.