I recently completed my second feature film while a senior at Penn State's New Media department. We used a Sony FX-1 HDV camera and utilized practical and available light and it looks great!!! We're hoping for a festival run in summer. Right now we're trying to figure out the marketing. I edited a quick teaser. Tell me what you think.
Here's the link:

http://www.youtube.com/watch?v=gajVxF5iZ5E

looks alright man, I like the fx1. Why not use lights? Just because no access and budget or what?

I like that effect, natural is realistic. Although it's only good when done right. I'd try to include artificial lighting in some areas that may require it.