Is there a way to edit multiple materials at the same time?

Using blender internal render and the standard non-node material interface, is there a way to edit property of all materials assigned to an object at the same time?

For example I have a person who has separate materials for arms / legs / chest / face / etc.; I want them all to have the same specular values, but it takes quite a bit to adjust it for every material on the model. Is there a way to tweak them all at the same time?

Thank you!

Maybe using a shared driver in all materials specular values?!

Had that thought but I have literally no idea how drivers work, it seems really complicated. Will see if I can understand them soon enough though, thank you!