On Android, you can just hold the search button to bring up voice search and say "navigate to $address" and google maps navigation will guide you to the address, no need to type anything. You can even say "navigate to $business_name" and it will lead you to the closest one.
I'm not sure if it was just a CM7 widget or not, but before I got my Galaxy Nexus, there was a widget available to do that. When you place the widget, you put in the address it should go to (one thing I didn't like is I don't remember autocomplete or any contact selection being available for it, so you had to know the address).
