>>Because that's cheating. ;-)
>Cheating? I guess I don't get it. Why is it cheating? Which part is
>cheating - alter table.. drop or index on... I guess I'm pretty thick
>here, or maybe you are just kidding?

Using DROP FOREIGN KEY to drop something that isn't a foreign key is "cheating". To create a regular index, use the INDEX ON command. There is no way I know of to create a regular index using ALTER TABLE or its ilk.