Multi-Currency Setup

[Tony]

I'd largely operate in 2 currencies simultaneously.  Is there a consensus
view on the right way to setup up accounts for this?  

I'm tempted to just pick a home currency (USD) and have child accounts for
all my income/expense accounts for the second currency (GBP).

E.g. I'd have such pairs as:

Assets:Current Assets:Cash
Assets:Current Assets:Cash:GBP

or

Expenses:Housing:Rent
Expenses:Housing:Rent:GBP

Is this a smart setup, or is there some other standard?

Thanks!
T