As a Brit, I have always said "Up to You" and I come from a generation that wasn't influenced by transatlantic films.  Any older Brits out there?  What do you think?

It's interesting to read this, because the divide is narrowing all the time in the UK. Someone of my age will have grown up in the UK being completely familiar with American English, and indeed some of those 'American' expressions are not uncommon to hear in the UK. 

'Home away from home'. I have said that expression in the past.

'Get going', again very common to hear nowadays in the UK. 'Move off?' Sounds pretty awkward to me, 'get going' sounds much better.

I have said 'bang to rights' but only rarely, and only then in a really emphatic or sarcastic way, it's not commonly a part of my vocabulary.

Both 'hang up' and 'ring off' exist in British English and are used but they mean different things. It's not the case that one is British, and one is American for the same thing.

'Hang up' is the common term in the UK for when someone puts the phone down on you.  'Ring off' means something different. If the phone 'rings off' it would be when the the phone is ringing, and you don't have the opportunity to answer it because you aren't quick enough. You aren't able to speak to the person, it is not that they put the phone down on you.

And I agree with Su.Ki about the distinction between 'up to you' and 'down to you.' They're not interchangeable.

Just a few more comments:

Would you catch someone red-handed (AmE) or would you bang someone to the rights (BrE)?

...no, not quite.

'Bang' isn't a verb here, and there is no 'the'. 'Bang to rights ' is a fixed phrase. The expression - which isn't at all common, by the way - is 'have someone bang to rights.' I don't know about other British people here, but I've never said this in my life, and have never heard it ouside the odd TV police drama.

But of course we also say 'catch someone red-handed'. This is a British expression which dates back as far as the 15th century, and is still used today on both sides of the Atlantic, so it's a little misleading to call it a 'US idiom'. Many of the other US expressions are also widely used in the UK. We also hang up, sleep in , and do the dishes sometimes in the UK.

That said, it's an interesting, entertaining article which I'm sure many italki users will enjoy. Well done.

Nicely written and reads really easily.  In response to the idiom "knock on wood", the original concept was the idea of ancient traditions knocking on trees to evoke or bring forth the spirits who lived in the trees, so that they would be protected from evil spririts when they spoke.  However it came to be simply "touch wood" later, I will never understand. 

Thanks again for this interesting article.

Thank you.