looking for alternative to MySQL's GROUP_CONCAT function

Hi all,

I'm looking into PostgreSQL. Coming from a MySQL
background, I have made heavy use of its very useful
GROUP_CONCAT function. You can read about the function
here:

http://dev.mysql.com/doc/refman/4.1/en/group-by-functions.html

Is there a PostgreSQL alternative to GROUP_CONCAT?

Thanks,
Ken