OODL: The uses of 'do'?

[DeRobertis]

I'd like a listof the uses of do. If there are some good ones, maybe it'll
be enough to justify the mess of using two interpreters...

Remember, I'm adding:

        much faster execution
        perl-like hashes

so don't say "in order to make it go fast" or "in order to name variables
at runtime"

I must confess, I hardly ever use 'do'.