I've heard that you should put it down on a makom patur while still walking. However, a true makom patur is tall and skinny, like a post, and therefore possibly difficult to find.
I've also heard that you walk into a reshus hayachid - private property - and, again, while still walking, hand it to another person who is also inside the same reshus hayachid. The rationale here is that "carrying" requires both an akira and hanacha, an uprooting and a setting. In this case, then, since you're still walking it's not considered a true hanacha.
Are either of these correct? If not, what should be done?