Yes Wampus, you can. If an office offers a write in candidate, you can press that selection. The screen clears and you are presented with a typewriter style keyboard on the screen so you can type the name of your candidate. Then you push a "Finished" button or some such and the screen displays what you typed in and offers you the ability to make changes.
It's really pretty user friendly. Just takes a little getting used to.
Sure wish it printed a paper receipt. I understand this feature will be added later.