Have you thought about shooting David Hobby's style with "on-axis fill"? (Canon version anyhow, he shoots Nikon).


It's about using hand held speedlight away from camera body as key lighting (your 430EXII), and the on-axis flash (can be the pop-up flash) to light up the shadows. This creates dimension and a nice "3D effect" as he puts it, and creates real depth in the portraits as opposed to a 2D flat look (you can see great examples on link below).


Here's an introduction post, andthis articletalks about how he used it on assignment.


The way he sets it up, even though it's off camera it still relies on TTL via cord. So once you have the settings right you can just go "Run and Gun" as he puts it []


*edit* - You also would want to diffuse your key light to reduce specular highlights and get softer lighting. Handheld, I would recommend Lumiquest SBIII (or SBII)