multiple manufacturers per product

For a book store, I want to change 'manufacturer' to author, which is easy enough. But some books have multiple authors and the manufacturer field only allows one selection per product. Is there an easy way to convert manufacturer to a multiple select, like with categories, stores and downloads?

Manufacturer makes more sense being Publisher don't you think? Would be good to keep track of publishers as manufacturers so you could create reports for books you need to re-order from each manufacturer for example. I feel as OpenCart evolves new features will be added around manufacturer regarding restocking.

Tags seem more suited to Author - I am investigating this now. Will let you know how I go.

there is not an easy way to convert manufacturer to multi select because there is not relational table in the database meaning it is a one to one relation unlike the category and stores that is a many to many because there is a seperate relational table that holds the relationships. To change that would be a lot of coding. I think reckoner is on a better path using the tags for author. You could then use something like my layered navigation and rename tag to author, or you could use something like the tag cloud, though it would have to be modified a bit to not format things in a cloud, but a list.

After investigating I found that tags work perfectly for authors. In the default template they are hyperlinked to search for other products with the same tags. This achieves all required author functionality (in my case anyhow).