help with group query

[Turin]

Hi everyone,
I need to make a query that show me details and grouping information at the same time.

This is my original table :

id who money
1 Henry 10
2 John 5
3 John 10
4 Mario 20

And I want to obtain this information:

id who money
1 Henry 10
Sum 10 <-- Groupping
2 John 5
3 John 10
Sum 15 <-- Groupping
4 Mario 20
Sum 20 <-- Groupping

I'm thinking that I can use a group by - rollup sentece.
But I don't know how to do it.
Any ideas?

Thanks in advance for your help
Regards