Walt was maticulous at picking up trash in the parks... so even if you saw, saw Iger or Roy in the parks..they would be picking up trash to!
A little OT- but on one of Eisners first trips to WDW, there seemed to be "strategically" placed trash on his walking route. He didn't want to pick it up, because his back hurt (big baby Eisner!!), but he did, because he knew if he didn't, there would be "you know what" to pay! AND, by the time he was done, his back pain was gone!