Hi M.,
There is a specific brand of cabinet/drawer locks that has a second safety feature -- once the child pull the drawer open about 1 1/2 inches, he cannot close it (and accidentally slam it on his fingers). We didn't find out about these until we had installed the regular kind all over the kitchen, otherwise I would have used them everywhere.
I'm hoping another Mom can give you the specific brand name, because I no longer remember it!
EDIT: the one we bought was not magnetic. It installs exactly like the regular kind. And I didn't notice any significant price difference. But, sorry, I still can't remember the brand. We either purchased them at Babies R Us or at Lowe's/Menards.