Concatenate Multiple Rows?

I can't figure out how to write an SQL query that concatenates one field from a list of records having other parameters in common. It is easier to show than explain. Take the data set:

Spec T_R Section
A008 23w 1
A008 23w 2
A008 23w 4

I need a query that returns a single record/row like this:

Spec T_R Section
A008 23w 1, 2, 4

Any help would be appreciated.I've had this problem more times than I can count. While I was writing my SQL Tutorial (http://www.bitesizeinc.net/index.php/sql.html), I ran across this function for MySQL :

group_concat(field)

Which concatenates the grouped results into a string. If you are using Oracle, you'll need a stored procedure...

-Chrissqlsql