Walkin' while patrolin'?

I know I probably won't end up using this, but I'm kinda curious. Is it possible to get creeps to walk while patroling/in-camp and run while fighting, all without using transformation abilities?

use walk speed and run speed values for the unit and increase the movespeed slightly when engaging enemies.

Thanks! I'll try that.

EDIT: So basically, set the Run/Walk animation speeds in the Object Editor, set the normal speed to slow, then add at least one character into the patrol group who has an area speed boost ability? (Guild Wars "Charge!" ability?)

That, or use the "acquires a target" event and manually modify their move speeds.