I see what you are saying about the scams, that didn't cross my mind. Yes, I think using words like locally owned etc would help. And, this is where an 'about us' page would help a lot too.
A professional blog might help ease your potential customers and differentiate your service from a scam. You could 'blog' about topics related to your industry, helpful hints, how to avoid a scam, etc. Plus blogs help a lot with your SEO and can be short and sweet. We use Word Press and it makes bloging easy and pretty painless.
I agree about your comment with the mobile devices. All they need to do is find your phone number!