Not a bad idea at all. I would be up for it. My schedule is sometimes crazy, other times pretty open, so it would all depend on the kind of week I was having.
I think this could be a really great way to help some of your business too. You'd strike up relationships with new people and maybe get more orders. Really, it's pretty clever!
I don't do cakes as a business, but would still be open to doing this for someone in my area if there were a need.