How to Combine multiple results in a subquery into a single comma-separated value

I've got two tables:

TableA
------
ID, Name

TableB
------
ID, SomeColumn, TableA_ID (FK for TableA)

The relationship is one row of TableA - many of TableB.

Now, I want to see a result like this:

ID     Name      SomeColumn

1.     ABC       X, Y, Z (these are three different rows)
2.     MNO       R, S

Solution
Sample data

declare @t table(id int, name varchar(20),somecolumn varchar(10))
insert into @t
    select 1,'ABC','X' union all
    select 1 ,'ABC','Y' union all
    select 1,'ABC','Z' union all
    select 2 ,'MNO','R' union all
    select 2 ,'MNO','S'

Query:

select ID,Name,
    stuff((select ',' + CAST(t2.SomeColumn as varchar(10))
     from @t t2 where t1.id = t2.id and t1.name = t2.name
     for xml path('')),1,1,'') SomeColumn
from @t t1
group by id,Name