Mav, that's the way I see it too. I have the impression that German is a good bet.. I've always had a fair share of Arabic friends, and it would mean I can learn first hand all that there is to know that's written or spoken in Arabic, which is pretty vast, i think.
Japanese would not pay off so much (especially considering the time it would take), from what I've experienced so far, but as Chairboy said, Mandarin seems like a good choice.. I expect, especially also considering how prolific they are by nature, they will have at least some involvement in my field of research, Neuroscience. That would be enough to warrant learning it.
Italian and latin would be pretty easy to learn if the need showed up. Russian too, once I know German.
Yep Vike, that's how I learned english: 3 months of crash courses weekly with an old english grandma in France, at 9 years old, then straight into Toronto.
Ike: Both..
Japanese being so time consuming is why I stopped a while ago. I'm looking to make this as efficient as possible.
Zarkov, thanks, I'll try that one out too.
And thanks Chairboy, I'll consider that..