Lingua Franca

So...how many languages do I want to deal with? I mean, it's certainly easier to handwave the differences in languages (think Star Trek) - but communication - and the potential for miscommunication is certainly fodder for adventures - or at least flavor for adventures.

But...How do you simulate the differences in languages? I mean, I hate (no that's not a strong enough term...um...loathe...despise...nah, hate is it) "speaking with funny voices" and doing accents and all that junk. I guess I'm more a wargamer than a roleplayer or whatever. I'd rather have some mechanic to simulate the differences in languages than to have to try to play it out (like, I speak a tiny bit of Spanish - and I can probably eek out a few words in a half dozen other languages - but, well, to try to make up a language, well, I'm not Tolkien...).

But, still, how many languages? Should there be some Lingua Franca that the characters can mostly communicate in? And if such a language exists, why bother with having any differences at all anyway?

Okay - no alignment languages (really, how do you speak Neutral?) - and...should every race have a different language? I mean, wouldn't goblins just learn a regional language? Is there a reason for them to have a language of their own? Or, maybe it could be...the dark tongue - the language of Chaos (oh, crap, that would be an Alignment Tongue, wouldn't it?) or...well, something. I'm thinking that Goblins, for example, ought to speak whatever language their masters speak - and I'm thinking it ought to be some kind of human tongue - maybe distorted...

Or...well, maybe I'll just handwave the whole thing...