Manufacturer sort in default sort drop down

Trying to put a manufacturer field in the default drop down sort, which currently has name, name desc, date, date desc, price, price desc and model but no Manufacturer, which to me in most cases seems a bit silly as that is how most customers are going to identify our products. I actually did this a while back so I know it is easy enough, but forgot what I did, comes with age, so if anyone has any ideas where I'd start please feel free to tell me.

vacuumwarlock:

Trying to put a manufacturer field in the default drop down sort, which currently has name, name desc, date, date desc, price, price desc and model but no Manufacturer, which to me in most cases seems a bit silly as that is how most customers are going to identify our products. I actually did this a while back so I know it is easy enough, but forgot what I did, comes with age, so if anyone has any ideas where I'd start please feel free to tell me.
What's this "default drop down sort" you speak of? What plugin is it part of?